Mean Aortic Pressure Research Articles

P1537 Myocardial work in patients with aortic stenosis before and short term after transcatheter aortic valve replacement

Abstract Objective The newly introduced noninvasive myocardial work analysis could potentially be beneficial in predicting the best timing for aortic valve replacement as well as clinical outcomes in patients with high grade aortic valve stenosis (AS), which is the leading valvular disease in the modern aging society. However, to date there is little data on the applicability of the method in the setting of extremely increased left ventricular (LV) afterload. Purpose In this pilot study, we aimed to apply myocardial work analysis in patients with increased LV afterload due to severe AS and to investigate the differences of myocardial work parameters in patients with different AS entities. In addition, we analyzed the early changes of myocardial work after the afterload reduction by transcatheter aortic valve replacement (TAVR). Methods We retrospectively studied echocardiographic data of 28 consecutive patients with severe AS before and 7 days after TAVR. Global Work Index (GWI), Global Constructive Work (GCW), Global Wasted Work (GWW) and Global Work Efficiency (GWE) were calculated using commercially available software based on noninvasive pressure-strain loops. In order to correct for underestimation of intraventricular pressure, we added the mean aortic valve pressure gradient to the peripheral systolic blood pressure used by the software. Results From the included patients (mean age 76 ± 10 years) 13 were classified as having normal flow (NF) severe AS, 8 had low flow low gradient (LFLG) and 7 paradoxical low flow low gradient (PLFLG) AS. GWI and GCW were significantly lower in patients with LFLG AS compared to patients with NF or PLFLG AS (936 ± 528 mmHg% vs. 2493 ± 485 mmHg% vs. 1959 ± 469 mmHg% [p < 0.005] and 1132 ± 477 mmHg% vs. 2770 ± 507 mmHg% vs. 2189 ± 603 mmHg%, [p < 0.005], respectively). 7 days after TAVR, GCW and GWI decreased significantly in patients with NF AS. In other AS entities, a trend towards increased GWI and GCW was observed, but the difference did not reach statistical significance. GWI and GCW remained significantly lower in LFLG AS group when compared to NF and PLFLG groups (1069 ± 378 mmHg% vs. 1919 ± 310 mmHg% vs. 2064 ± 842 mmHg% [p < 0.005] and 1286 ± 346 mmHg% vs. 2107 ± 258 mmHg% vs. 2227 ± 949 mmHg% [p < 0.005]) early after TAVR. GWE and GWW did not differ between the groups and were not influenced by TAVR. Conclusion In this pilot study we applied the adapted myocardial work analysis in patients with increased afterload due to severe AS. We have shown that GCW and GWI are significantly higher in patients with NF AS when compared to LFLG and PLFLG AS. The differences between the groups persisted early after TAVR in spite of significant reduction of GWI and GWC in patients with NF AS. The clinical and prognostic importance of these findings are still to be investigated in a bigger cohort study.

P1575 Preserved myocardial work efficiency after transcatheter aortic valve implantation-induced left bundle branch block

Abstract Background Left bundle branch block (LBBB) frequently complicates transcatheter aortic valve implantation (TAVI), but may not induce classical mechanical dyssynchrony typically observed in heart failure patients with LBBB. Non-invasive estimated myocardial work by pressure strain-loops is a novel method for evaluation of left ventricular (LV) performance including loading conditions and identifies responders to cardiac resynchronization therapy. Assessment of myocardial work in TAVI-induced LBBB has, however, not been performed earlier. Purpose We aimed to evaluate myocardial performance in TAVI-induced LBBB by myocardial work. Methods Patients with severe aortic stenosis (AS) and normal ventricular conduction undergoing transfemoral TAVI were included. TAVI-induced LBBB was defined according to strict ECG criteria. In addition to standard echocardiographic parameters, we performed speckle tracking echocardiography (STE) within 2 days post procedure. Post-procedural myocardial work was estimated by commercially available software, combining LV strain by STE and a non-invasively estimated LV pressure curve. Peak systolic LV pressure was assumed to be equal to the sum of peak arterial cuff pressure and mean aortic valve pressure gradient. The proportion of constructive work relative to the sum of wasted and constructive work was expressed as myocardial work efficiency (Figure). A global work efficiency < 90 % was considered abnormal according to the recently published EACVI NORRE study. Results We included 109 consecutive patients undergoing TAVI (83 ± 7 years old, 54 % women, logistic Euroscore 16 ± 10) with severe AS (valve area 0.7 ± 0.2 cm2, mean transvalvular gradient 54 ± 18 mmHg), QRS duration 94 ± 10 ms, and a relatively preserved LV ejection fraction (54 ± 9%). New-onset LBBB was observed in 28 patients (26 %) after TAVI. Although post-procedural myocardial work efficiency was slightly better in patients who retained normal ventricular conduction than those with TAVI-induced LBBB (93.6 ± 2.5% vs 91.2 ± 3.4%, p = 0.004), both groups of patients had global myocardial work efficiency within the normal reference range. Conclusions Patients with TAVI-induced LBBB have preserved work efficiency despite gross electrical block satisfying strict ECG criteria. The reduced myocardial work efficiency in TAVI-induced LBBB was within the reference range of normal in the recently published EACVI NORRE study. The preservation of myocardial work in TAVI-induced LBBB may explain why LBBB as a complication to TAVI does not necessarily imply poor prognosis. Abstract P1575 Figure.

Echocardiographic outcomes from seven randomized trials of transcatheter versus surgical aortic valve replacement.

We performed meta-analyses of echocardiographic outcomes, including postprocedural aortic valve area (AVA), aortic valve mean pressure gradient (MPG), and paravalvular aortic regurgitation (PAR), exclusively from all currently available randomized controlled trials (RCTs) of transcatheter aortic valve implantation (TAVI) versus surgical aortic valve replacement (SAVR). To identify all RCTs providing echocardiographic outcomes (AVA, MPG, and PAR) up to 2 years after TAVI versus SAVR, PubMed and ClinicalTrials.gov were searched through June 2019. Mean differences in AVA (and MPG) between the TAVI and SAVR groups and odds (or hazard) ratios of at least moderate PAR for TAVI versus SAVR were pooled using the random-effects meta-analysis. We identified seven eligible RCTs. At 30 days (P = 0.004), 1 year (P = 0.006), and 2 years (P = 0.03), AVA was significantly larger after TAVI than after SAVR. After TAVI than after SAVR, MPG was significantly lower at 30 days (P = 0.03) and 2 years (P = 0.01), and nonsignificantly lower at 1 year (P = 0.06). At 30 days (P < 0.00001), 1 year (P < 0.00001), and 2 years (P < 0.00001), incidence of at least moderate PAR was significantly greater after TAVI than after SAVR. On the basis of the present meta-analyses of all the seven currently available RCTs, AVA is larger, MPG is lower, and incidence of at least moderate PAR is greater 30 days, 1 and 2 years after TAVI than after SAVR.

P289 Aortic valve resistance risk-stratifies low-gradient aortic stenosis

Abstract Background Grading the severity of aortic stenosis (AS) is challenging, since there is a discrepancy between aortic valve area (AVA) and mean pressure gradient (mPG). Arotic valve resistance (RES) has been proposed as a usuful descriptor of AS severity, but it is not commonly used for clinical decision-making, because its robust validation of clinical-outcome efficacy is lacking. This study aimed to investigate whether RES holds an incremental value for risk-stratifying AS. Methods This study recuited 565 AS patients (AVA &amp;lt; 1.5cm²) referred to echocardiography for valve assessment. The patients were divided into three different groups, according to the guidelines: high-gradient AS (HG-AS, mPG≥40mmHg, n = 157), low-gradient AS (LG-AS, mPG &amp;lt; 40mmHg + AVA ≤ 1.0cm², n = 155) and moderate AS (Mod-AS, mPG &amp;lt; 40mmHg + AVA &amp;gt; 1.0cm², n = 253). RES was calculated from Doppler measurement of mPG and stoke volume. The diagnositic cutoff point for RES was determined at 190 dynes × s×cm-5 by substituting AVA = 1.0cm² and mPG = 40mmHg into the definition formula of RES and Gorlin formula. The patients were followed up for 2 years. The endpoint was a composite of cardiac death, hospitalization for heart failure and aortic valve replacement necessitated by the development of AS-related symptoms. Result Kaplan-Meier analyses showed that LG-AS exhibited an intermediate outcome between HG-AS and Mod-AS (event-free survival at 2 years = 20.9% for HG-AS, 59.7% for LG-AS, 89.9% for Mod-AS, p &amp;lt; 0.001, figure A). When LG-AS was stratified by RES, the survival curves showed a significant separation (event-free survival at 2 years = 35.3% for high RES, 70.7% for low RES, p &amp;lt; 0.001, figure B). This trend persisted even when analysed separately for norml (stroke volume index &amp;gt; 35ml/m²) and low (stroke volume index ≤ 35ml/m²) flow state ((normal flow) event-free survival at 2 years = 38.7% for high RES, 70.4% for low RES, p = 0.023, figure C; (low flow) event-free survival at 2 years = 26.7% for high RES, 74.6% for low RES, p &amp;lt; 0.001, figure D). Conclusion This study confirmed the clinical efficacy of RES for risk-stratifying LG-AS patients. Abstract P289 Figure.

Assessment of the prognostic significance of low gradient severe aortic stenosis and preserved left ventricular function requires the integration of the consistency of stroke volume calculation and clinical data.

This study was to evaluate the prognostic significance of low gradient severe aortic stenosis (LG SAS) and preserved left ventricular ejection fraction (LVEF) with the integration of echocardiographic and clinical data. The study included 172 patients with LG SAS (AVAi≤0.6cm2 /m2 , mean aortic pressure gradient<40mmHg) and LVEF (≥ 50%). LV outflow tract diameters were measured at both the aortic valve annulus and 5mm below the annulus for the measurement consistency. Patients were divided into the low flow LG SAS (LF/LG SAS: SVi<35mL/m2 and AVAi≤0.6cm2 /m2 ) and normal-flow LG SAS groups (NF/LG SAS: SVi≥35mL/m2 and AVAi≤0.6cm2 /m2 ). Echocardiographic findings and clinical data were systematically analyzed with mean follow-up of 3.0±1.6years. LF/LG SAS had significantly smaller AVAi, lower SVi, a higher prevalence of atrial fibrillation (28% vs 12% P=.01) and diabetes (47% vs 27% P=.007) and lower 3-year cumulative survival than NF/LG SAS. Multivariable analysis showed that dyspnea, renal dysfunction (CI 1.42-3.99, P<.01), left atrial diameter, and SVi were independently associated with an increased risk for all-cause mortality. Aortic valve intervention (AVI) improved survival in LF/LG SAS (68% vs 48%, P<.05) in comparison with medical management (HR: 4.20, CI: 1.12-15.76, P=.03), but only modestly in NF/LG SAS (75% vs 65% P>.05). Outcome of LG SAS was independently associated with clinical characteristics. AVI likely improved outcome of LF/LG SAS who had high-risk clinical characteristics and unfavorable echocardiographic findings.

624 Is TAVI a useful procedure in paradoxical low flow-low gradient aortic stenosis? A long-term mortality study

Abstract Background Clinical outcomes of patients with paradoxical low-flow, low-gradient aortic stenosis (PLF-LG) undergoing valve replacement are controversial. PLF-LG is a combination of a small aortic valve area (AVA &amp;lt; 1cm²), a preserved left ventricular (LV) ejection fraction (LVEF≥50%), and a ‘paradoxical’ low mean gradient due to the presence of low LV stroke volume (≤35 mL/m²). The low flow state is explained by the presence of a high afterload and pronounced LV concentric remodeling, with impaired LV filling. Surgical aortic valve replacement has been associated with very positive outcomes in normal-flow high-gradient (NF-HG) AS, whereas poorer outcomes has been reported in patients with PLF-LG AS. Purpose The aim of this study is to determine the clinical outcomes in patients with PLF-LG AS undergoing transcatheter aortic valve implantation (TAVI) compare to NF-HG patients. Methods A total of 624 patients (age 81 ± 7 years) with symptomatic severe AS and preserved LVEF who underwent TAVI, was enrolled and divided in 2 groups: group NF-HG included 554 patients (89%) and group PLF-LG including 70 patients (11%). At 1-year follow-up, death and clinical events were reported. Results TAVI was feasible in all patients. A significant reduction in mean aortic pressure gradient was observed after TAVI both in PLF-LG (baseline, 30 ± 6 mmHg; 1-year, 12 ± 4 mmHg; p &amp;lt; 0.001) and in NF-HG (baseline, 55 ± 12 mmHg; 1-year, 11 ± 4 mmHg; p &amp;lt; 0.001) together with an increase in AVA (PLF-LG: baseline, 0.73 ± 0.16 cm², 1-year: 1.82 ± 0.43 cm², p &amp;lt; 0.001; NF-HG: baseline, 0.66 ± 0.18 cm², 1-year: 1.84 ± 0.38cm², p &amp;lt; 0.001). Perioperative mortality at 30-days was similar in group NF-HG (17/554, 3%) and in group PLF-LG (2/70, 3%). Figure shows the survival curves up to 5 years follow-up according to the two groups. PLF-LG and HG-AS had similar survival rate throughout the long-term follow-up. Similarly, rehospitalization rate was not different in the two groups (PLF-LG: 12% vs NF-HG: 7%, p = 0.127). Conclusions Differently from surgical series, TAVI in PLF-LG AS is a useful procedure showing similar mortality and rehospitalization rates compared to NF-HG AS patients. Abstract 624 Figure. Survival curve

P18 The utility and validity of intracoronary administration of nicorandil alone for the measurement of fractional flow reserve in patients with intermediate coronary stenosis

Abstract Backgrand Recently, intracoronary nicorandil (ICN) administration in addition to intravenous adenosine 5"-triphosphate (IVATP) is generally used to achieve maximal hyperemia for evaluating fractional flow reserve (FFR). This study investigated the usefulness and safety of ICN alone compared with IVATP and ICN during IVATP for the achievement of maximal hyperemia in patients with suspected angina pectoris. Methods Two-hundred-ten angiographically intermediate lesions in two-hundred-seven patients who underwent FFR assessments were enrolled. FFR was measured after ICN (2mg/5seconds), IVATP (150µg/kg/min) for 2 minutes, IVATP (210µg/km/min) for 2 minutes, and ICN (2mg/5seconds) during IVATP (150µg/kg/min). Maximal hyperemia was defined as the lowest FFR measured among each method. Results During the protocol, 92% of patients achieved maximal hyperemia with ICN2mg, 54% with IVATP 150µg/kg/min, 91% with IVATP 210µg/kg/min, and 99% with ICN2mg during IVATP 150µg/kg/min, respectively. The FFR obtained with ICN2mg were strongly correlated with those obtained with ICN2mg during IVATP150µg/kg/min (r²=0.93, P&amp;lt; 0.001). The mean aortic pressure drop during hyperemia was significantly lower in ICN2mg than in IVATP 150µg/kg/min, IVATP 210µg/kg/min, and ICN2mg during IVATP 150µg/kg/min(9 ± 10, 11 ± 14, 24 ± 17, and 27 ± 19mmHg, p &amp;lt; 0.001, respectively). Despite no side effects reported during hyperemia with ICN2mg alone, transient atrioventricular block was observed in 1(1%) patient with IVATP 150µg/kg/min and 9(4%) patients with IVATP 210µg/kg/min. Also, 20 (10%) patients with IVATP 150µg/kg/min and 56(27%) with IVATP210µg/kg/min experienced chest discomfort during hyperemia. Conclusions The intracoronary administration of NIC2mg is safe and well tolerated, and shortens the procedure. Furthermore, intracoronary NIC2mg produced a more pronounced hyperemia than IVATP and may be the preferred mode of application for the assessment of FFR.

Prognostic interest of energy loss index in patients with low gradient severe aortic stenosis and preserved ejection fraction

Assessment of pressure recovery adjusted indexed aortic valve area (AVAi) – energy loss index (ELI) – has been shown of prognostic interest for patients with asymptomatic and/or mild aortic stenosis (AS), but limited data are available in the setting of low gradient aortic stenosis (LG-AS). We hypothesized that among patients with LG-AS and preserved left ventricular ejection fraction (LVEF), reclassification of AS severity as moderate by pressure recovery adjusted indexed aortic valve area (AVAi) may identify a subgroup of patients with a better outcome. A total of 379 patients with LG-AS (defined by AVAi ≤ 0.6 cm 2 /m 2 and mean aortic pressure gradient < 40 mmHg) and preserved LVEF ≥ 50%were studied. Reclassification as moderate AS by ELI was defined as AVAi ≤ 0.6 cm 2 /m 2 but with an ELI > 0.6 cm 2 /m 2 . Cardiac events (cardiac mortality and/or need for aortic valve replacement [AVR]) during follow-up were studied. One hundred and forty eight patients (39%) were reclassified as moderate AS by ELI. Reclassification as moderate AS was independently associated with absence of coronary artery disease, decreased body surface area, normal flow status, and decreased left ventricular mass index (all P < 0.05). After adjustment for variables of prognostic interest, reclassification as moderate AS by ELI was associated with a considerable reduction of risk of cardiac events (adjusted HR 0.50 [95% CI, 0.34–0.73]; P < 0.001), need for AVR (adjusted HR 0.56 [95% CI, 0.36–0.87]; P = 0.008) and cardiac mortality (adjusted HR 0.44 [95% CI, 0.21–0.91]; P = 0.027) ( Fig. 1 ). In patients with low gradient severe AS and preserved LVEF, calculation of ELI permits to reclassify almost 40% of patients as having moderate AS. These reclassified patients have a considerable reduction of the risk of cardiac events during follow-up. Calculation of ELI is useful for decision making in patients with low gradient severe AS and preserved ejection fraction.

Loss of Endothelial Endoglin Promotes High-Output Heart Failure Through Peripheral Arteriovenous Shunting Driven by VEGF Signaling.

ENG (endoglin) is a coreceptor for BMP (bone morphogenetic protein) 9/10 and is strongly expressed in endothelial cells. Mutations in ENG lead to the inherited vascular disorder hereditary hemorrhagic telangiectasia characterized by local telangiectases and larger arteriovenous malformations (AVMs); but how ENG functions to regulate the adult vasculature is not understood. The goal of the work was to determine how ENG maintains vessel caliber in adult life to prevent AVM formation and thereby protect heart function. Genetic depletion of endothelial Eng in adult mice led to a significant reduction in mean aortic blood pressure. There was no evidence of hemorrhage, anemia, or AVMs in major organs to explain the reduced aortic pressure. However, large AVMs developed in the peripheral vasculature intimately associated with the pelvic cartilaginous symphysis-a noncapsulated cartilage with a naturally high endogenous expression of VEGF (vascular endothelial growth factor). The increased blood flow through these peripheral AVMs explained the drop in aortic blood pressure and led to increased cardiac preload, and high stroke volumes, ultimately resulting in high-output heart failure. Development of pelvic AVMs in this region of high VEGF expression occurred because loss of ENG in endothelial cells leads to increased sensitivity to VEGF and a hyperproliferative response. Development of AVMs and associated progression to high-output heart failure in the absence of endothelial ENG was attenuated by targeting VEGF signaling with an anti-VEGFR2 (VEGF receptor 2) antibody. ENG promotes the normal balance of VEGF signaling in quiescent endothelial cells to maintain vessel caliber-an essential function in conditions of increased VEGF expression such as local hypoxia or inflammation. In the absence of endothelial ENG, increased sensitivity to VEGF drives abnormal endothelial proliferation in local regions of high VEGF expression, leading to AVM formation and a rapid injurious impact on heart function.

Early clinical outcomes of simple pannus removal for mechanical aortic valve stenosis

BackgroundThis study aimed to confirm the safety and feasibility of simple pannus removal in patients with mechanical aortic valve dysfunction for pannus overgrowth by evaluating its early clinical outcomes.MethodsFrom March 2015 to April 2019, 24 consecutive patients with mechanical aortic valve dysfunction due to subaortic pannus underwent reoperation. In 12 patients the repeat aortic valve replacement (AVR) was performed, and 12 received the simple pannus removal to preserve the previously implanted prosthesis.ResultsThere was only 1 in-hospital death in simple pannus removal group. Significant differences were obtained between procedures in cardiopulmonary bypass (CPB) and aortic cross-clamp time (128.7 vs 179.7 and 74.2 vs 132.7 mins, respectively, P < 0.05). The C-reactive protein (CRP) in simple pannus removal group was lower on the first day (0.13 ± 0.09 vs 0.31 ± 0.22 mg/dl, P < 0.05) and continued to be lower within 1 week after operation. There was no significant difference between procedures in aortic transvalvular peak velocity and transvalvular mean pressure gradient (TMPG) (2.6 ± 0.4 vs 2.5 ± 0.4 m/s and 13.2 ± 3.6 vs 11.6 ± 2.6 mmHg, respectively, P > 0.05) in echocardiography 1 week after operation. In addition, the aortic transvalvular peak velocity and TMPG in echocardiography 1 week after operation in pannus removal group between the repeat and initial surgery were not statistically significant (2.6 ± 0.4 vs. 2.5 ± 0.3 m/s, 13.2 ± 3.6 vs. 13.0 ± 3.5 mmHg, P > 0.05).ConclusionsSimple pannus removal was a safe and effective procedure with satisfied early clinical outcomes for pannus overgrowth in mechanical aortic valve. However, further randomized and long-term follow-up studies were warranted to determine the clinical effects of the simple aortic pannus removal.

Abstract 368: A Cardiac Arrest Simulation-Based Feasibility Cadaver Study Investigating Time for Semi Surgical Cut Down Procedure Followed by Insertion of a Novel REBOA Catheter

Aim: Non-traumatic cardiac arrest is a major public health problem that carries an extremely high mortality rate. The Resuscitative endovascular balloon occlusion of the aorta (REBOA) procedure is currently being discussed as a possible technique to be used during Advanced Life Support (ALS) in humans with Cardiac arrest (CA). The aim of this study was to assess the training of emergency physicians in the procedures related to insertion of a novel REBOA catheter. Methods: We developed a training program using a simulated CA model on human cadavers. CPR was performed using the LUCAS device (Stryker/Jolife AB, Lund, Sweden). All cadavers were hemodynamically monitored. The Neurescue REBOA catheter (Neurescue REBOA device, Neurescue ApS, Copenhagen, Denmark) was inserted using a semi-surgical cut-down and sheath placement technique. Time needed to perform the procedures was measured. The procedures were instructed by 2 experts using video, procedural simulation on manikin and full-scale training on cadavers. Results: Six human cadavers were enrolled and a total of 12 procedures were performed by 2 expert investigators and 10 novice investigators. Eight semi-surgical cut-down producers including placements of the introducer sheath were performed on the first attempt and 4 required a second attempt. The median time required for the semi-surgical cutdown procedure and sheath placement by the novice investigators was: 6 min 48 sec (Min: 3 min 45 sec and Max: 26 min 25 sec). The median time required for the insertion and occlusion of the REBOA catheter by the novice investigators was: 3 min 22 sec (Min: 1 min 22 sec and Max: 7 min 5 sec). The median time required for full insertion for the novice investigators was: 11 min 14 sec (Min: 6 min 49 sec and Max: 28 min 15 sec). The mean aortic pressure during compression was: 31.9 mmHg (±17.0). Conclusions: Semi surgical cut-down and introducer sheath placement were performed in 1 or two 2 attempts for all novice investigators with an insertion time compatible with ALS during refractory CA. Simulation training on cadavers brings clinical realism and could be an important addition to the use of manikin or animal training models.

Study on in vitro performance verification protocol for left ventricular assist device.

In vitro performance verification of ventricular assist devices using a mock circulatory loop is a prominent step to guarantee the system responses and the device performance and safety before the in vivo tests and ultimately clinical trials. In this article, we performed a comprehensive literature research to establish a verification matrix consisting of 12 test cases, defined by a set of physiological parameters which are commonly used to characterize a physiological condition. The clinical hemodynamic indicators for defining successful mechanical support were used as the acceptance criteria. A mock circulatory loop was customized to simulate the test cases, and a full verification protocol was described in details. An example left ventricular assist device was incorporated in the loop to accomplish a standard ventricular assist device performance verification. The test cases based on clinical data with sufficient safety margin represent our understanding in defining the extremes of operation. The mock circulatory loop was capable of generating the test conditions in the verification matrix and reproducing the Frank-Starling law of the native heart. The effect of the left ventricular assist device assistance (characterized by the total systemic flow, mean aortic pressure, and left atrial pressure) was well verified by the proposed protocol and acceptance criteria. To date, all left ventricular assist devices made in China have been evaluated according this protocol and some of them have entered the clinical trial stage. We are closely observing the clinical data in order to further improve the performance of the platform and encourage more advances in mechanical circulatory assist devices.

Cardiac power output accurately reflects external cardiac work over a wide range of inotropic states in pigs

BackgroundCardiac power output (CPO), derived from the product of cardiac output and mean aortic pressure, is an important yet underexploited parameter for hemodynamic monitoring of critically ill patients in the intensive-care unit (ICU). The conductance catheter-derived pressure-volume loop area reflects left ventricular stroke work (LV SW). Dividing LV SW by time, a measure of LV SW min− 1 is obtained sharing the same unit as CPO (W). We aimed to validate CPO as a marker of LV SW min− 1 under various inotropic states.MethodsWe retrospectively analysed data obtained from experimental studies of the hemodynamic impact of mild hypothermia and hyperthermia on acute heart failure. Fifty-nine anaesthetized and mechanically ventilated closed-chest Landrace pigs (68 ± 1 kg) were instrumented with Swan-Ganz and LV pressure-volume catheters. Data were obtained at body temperatures of 33.0 °C, 38.0 °C and 40.5 °C; before and after: resuscitation, myocardial infarction, endotoxemia, sevoflurane-induced myocardial depression and beta-adrenergic stimulation. We plotted LVSW min− 1 against CPO by linear regression analysis, as well as against the following classical indices of LV function and work: LV ejection fraction (LV EF), rate-pressure product (RPP), triple product (TP), LV maximum pressure (LVPmax) and maximal rate of rise of LVP (LV dP/dtmax).ResultsCPO showed the best correlation with LV SW min− 1 (r2 = 0.89; p < 0.05) while LV EF did not correlate at all (r2 = 0.01; p = 0.259). Further parameters correlated moderately with LV SW min− 1 (LVPmaxr2 = 0.47, RPP r2 = 0.67; and TP r2 = 0.54). LV dP/dtmax correlated worst with LV SW min− 1 (r2 = 0.28).ConclusionCPO reflects external cardiac work over a wide range of inotropic states. These data further support the use of CPO to monitor inotropic interventions in the ICU.

P2453Value of pre-operative left atrial minimum volume as a surrogate for post-operative symptoms in patients with aortic stenosis who underwent aortic valve replacement

Abstract Background Previous reports have shown that symptoms after aortic valve replacement (AVR) are not uncommon depending on severity of myocardial fibrosis in patients with severe aortic stenosis (AS). Pre-operative minimum left atrial volume (LAVmin) at end-diastole determined by direct exposure of left ventricular end-diastolic pressure may be used as a surrogate for post-operative symptoms in patients with severe AS undergoing AVR. Purpose The purpose of this study was to examine the value of pre-operative echocardiographic LAVmin index (LAVImin) to predict post-operative symptomatic status after AVR in patients with severe AS. Methods The study population consisted of 219 patients with severe AS who underwent AVR and were followed up for 1000 days after AVR. Pre-operative maximum LAV index (LAVImax), LAVImin, LA emptying fraction (LAEF), LV volume indexes, LV ejection fraction (LVEF) by biplane Simpson's method, aortic valve area index (AVAI), mean aortic valve pressure gradient (mAV-PG), E/A, mean E/e' from LV inflow and mitral annular velocity, and pulmonary artery systolic pressure (PASP) were evaluated by Doppler echocardiography. Results After exclusion of 136 patients who met the exclusion criteria (atrial fibrillation, significant coronary artery disease, significant mitral valve diseases, pacemaker rhythm, and inadequate echocardiographic images), the final study population consisted of 75 patients (75±7 years old, 46 female). During a follow-up, 19 patients (25%) complained post-operative symptoms. There were no significant differences in pre-operative serum hemoglobin, creatinine, BNP, chronic obstructive pulmonary disease, hypertension, diabetes, LV volume indexes, LVEF, AVA, mAV-PG between patients with and without post-operative symptoms. There were significant differences in pre-operative LAVImax, LAVImin, and LAEF between patients with and without post-operative symptoms. (60±15 vs 47±15 ml/m2, 45±15 vs 28±1 ml/m2, and 29±12 vs 42±11 ml/m2, respectively). E/A, mean E/e', and PASP in patients with symptoms were significantly greater compared with patients without symptoms (1.0±0.3 vs 0.7±0.2, 25±3 vs 18±2, 44±17 vs 32±9 mmHg, respectively). In the multivariate analysis, pre-operative LAVImin was the independent predictor of the post-operative symptomatic status after AVR (odds ratio: 1.11, 95% confidence interval: 1.04 - 1.18). Receiver operating characteristic analysis revealed that area under the curve (AUC) of LAVImin (cutoff: 30ml/m2) for post-operative symptoms was the largest (0.84) among the other echocardiographic parameters, and significantly larger than that of mean E/e' (0.67, *p&lt;0.01) and LVEF (0.53, **p&lt;0.05) (figure). Figure 1. ROC analysis Conclusions The present results suggest that pre-operative echocardiographic LAVImin may be used as a surrogate for post-operative symptomatic status after AVR in patients with severe AS.

P4583Effect of permanent right internal mammary artery occlusion on right coronary artery collateral function. a randomized controlled trial

Abstract Background Extracardiac coronary artery supply via the pericardiophrenic branch of the internal mammary arteries (IMA) has been well documented anatomically. Recently, a proof-of-concept study has found functional relevance of these anastomoses in patients with coronary artery disease (CAD) during a brief right coronary artery (RCA) occlusion. Purpose The aim of the present randomized controlled, single-blind trial was to investigate the effect of permanent right IMA (RIMA) occlusion on RCA collateral flow index (CFI) and on the occurrence of angina pectoris. We hypothesized that the change in RCA CFI from baseline to follow-up examination is higher in the group of patients with than without permanent RIMA occlusion. Methods One hundred patients with CAD were randomly allocated (1:1) to permanent RIMA device occlusion at baseline or to no RIMA occlusion (sham control group). The primary study endpoint was CFI change in the RCA from baseline to the 6-week follow-up examination. CFI is the ratio between mean coronary occlusive and aortic pressure both subtracted by central venous pressure as obtained during a 1-minute proximal RCA balloon occlusion. RCA CFI was measured at baseline before RIMA occlusion or the sham procedure and at the follow-up invasive exam. At the end of the same occlusion, occurrence of angina pectoris was assessed. Percutaneous coronary intervention (PCI) of the RCA was deferred until after follow-up RCA CFI measurement. Results There were 51 patients in the RIMA occlusion (verum) group and 49 patients in the sham control group. PCI in the left coronary territory was performed at baseline for clinical reasons in 27 patients of the verum group and in 25 patients of the sham control group. There were no differences in clinical characteristics at baseline between the groups (age 68±12 years, 88 men). RCA CFI change during the 6 weeks of follow-up was equal to +0.028±0.077 in the verum group and −0.026±0.079 in the sham control group (p=0.0017). Angina pectoris during CFI measurement had disappeared at follow-up exam in 30% of the verum group and in 2% of the sham control group (p=0.0013). Conclusions Right coronary collateral function is augmented 6 weeks after permanent RIMA occlusion when compared to sham treatment. This manifests as less frequent angina pectoris during myocardial ischemia among patients with RIMA occlusion. Acknowledgement/Funding This study was supported by a grant from the Swiss National Science Foundation for Research (grant #32003B_163256/1 to CS).

P5563Biopsy proven myocarditis: clinical and instrumental predictors of adverse prognosis at presentation

Abstract Background Myocarditis is an insidious and potentially fatal illness with different clinical presentations and an unpredictable course. Prompt recognition of high risk patients is of paramount importance in preventing major adverse events. Purpose To identify predictors of dismal prognosis in a large cohort of patients with biopsy proven myocarditis. Methods Univariate analysis was used to identify predictors of death and heart transplant in a prospective cohort of 366 patients with biopsy proven myocarditis (aged 38±17, male 66%) using student's test and contingency tables as appropriate. Results At the time of follow up 46 patients (13%) were dead or received heart transplant (DHTX), 283 (77%) were alive (A) and 37 (10%) lost at follow up. Age at presentation was 33±20 y in DHTX v.s 39±15 in A cohort (p=0.057). Clinical features predicting adverse prognosis included female gender (p=0.002), heart failure at presentation (p=0.000), NYHA class II to IV (p=0.000). Clinical and radiographic signs of both left and right heart failure suggested worse outcome (p=0.000) as well as ongoing anticoagulation therapy (p=0.009). On ECG right (R) or left (L) axis deviation was a strong predictor of events (p=0.000). From an echocardiography perspective the presence of mild to severe mitral regurgitation (p=0.03), reduced left ventricular systolic function (FE) (p=0.000), reduced right ventricular fractional area change (FAC) (p=0.035) was strongly correlated to death or heart transplant. On cardiac catheterization the variables predicting unfavourable outcome included reduced left ventricular systolic pressure (LVSP) (p=0.000), reduced mean aortic pressure (mAP) (p=0.002), increased mean right atrial pressure (RAP) (p=0.001), FE on angiography (p=0.000). On cardiac biopsy (Bx) negative predictors were giant cell histology type (p=0.000) and PCR positive for viral genome (p=0.02) particularly for parvovirus B19 (p=0.04), adenovirus (p=0.04), and Epstein Barr virus (EBV) (p=0.03). See Tab 1 Table 1 Conclusion Female gender, HF like presentation, reduced LV and RV systolic function, R or L axis deviation on ECG, presence of viral PCR or giant cell histology on Bx, reduced LVSP and mAP; increased RAP may be useful parameters to identify high risk patients on presentation. This may increase clinical efforts and surveillance in this subgroup in order to reduce the incidence of major adverse events.

P5632Different impact of lesion length on fractional flow reserve in intermediate coronary lesions between each coronary artery

Abstract Background Previous studies reported that lesion length was an important geometric parameter in addition to the degree of stenosis in the determinant of functional significance of coronary artery stenosis. Nevertheless, the optimal cutoff value of lesion length for predicting functional significance for each coronary artery has not yet been evaluated, though previous studies revealed that the cutoff value of minimum lumen diameter measured on coronary angiography (CAG) to predict fractional flow reserve (FFR) &lt;0.80 is different for each coronary artery Purpose This study evaluated whether the impact of lesion length on functional significance is similar between each coronary artery for lesions with intermediate stenosis. Methods Patients with suspected coronary artery disease who had at least one intermediate coronary lesion (luminal diameter stenosis of 70 to 80% by visual estimation on CAG) and underwent FFR measurement for the evaluation of myocardial ischemia were evaluated. Quantitative coronary angiography analysis including percent diameter stenosis and lesion length was performed. FFR was measured as the ratio of the mean distal coronary artery pressure to the mean aortic pressure during maximal hyperemia induced by intravenous infusion of adenosine triphosphate (150 μg /kg/min). The area under the receiver operating characteristics (ROC) curve was estimated for the best cutoff value as a predictor of FFR value of ≤0.80 for each coronary artery. Results A total of 221 de novo lesions that underwent FFR measurement were enrolled. The average FFR value was 0.81±0.07. Although lesion length was similar among the lesions with an FFR &gt;0.80 at different locations, the mean lesion length was significantly longer for lesions in the right coronary artery (RCA) with an FFR ≤0.80 than for those in the left anterior descending artery (LAD) and left circumflex artery (13.4±3.4 versus 8.6±3.1 versus 12.0±3.7 mm, p&lt;0.001). ROC analysis demonstrated that the optimal cutoff value of lesion length for predicting an FFR ≤0.80 was 10.0 mm in the LAD (0.56 area under the curve, 48% sensitivity, 76% specificity), whereas 13.1 mm in the RCA (0.84 area under the curve, 67% sensitivity, 93% specificity) (Figure). ROC analysis of LL for FFR≤0.80 Conclusions A longer lesion length is required to achieve FFR&lt;0.80 in the RCA than in the other arteries. This may suggest the low possibility of an FFR ≤0.80 when stenosis is focal and short in the RCA with stenosis of 70 to 80% by visual estimation on CAG.

P2702Assessment of endothelial shear stress and functional significance of coronary lesions by computed tomography coronary angiography (CTCA) and computational fluid dynamics: a comparison with PET

Abstract Background The feasibility of assessing endothelial shear stress (ESS) in coronary lesions by non-invasive imaging and its potential role in different clinical settings has been recently explored. However, the relationship of ESS with functional indices derived by computed tomography coronary angiography (CTCA) and its value in predicting perfusion changes by quantitative positron emission tomography (PET) downstream stenotic vessels has not been assessed. Purpose To investigate the feasibility of calculating local ESS, its relationship with stenosis severity as well as with virtual functional assessment index (vFAI), and the comparative performance of the two parameters for predicting impaired coronary vasodilating capability in terms both of stress myocardial blood flow (MBF) and myocardial flow reserve (MFR) in patients submitted to CTCA. Methods Thirty-two patients (23 male-9 female, mean age 65.6±7.2 years) with intermediate pre-test likelihood of coronary artery disease (CAD), who were enrolled in the EVINCI and SMARTool projects, and had undergone CTCA with vFAI and PET myocardial perfusion imaging with 15 O-water or 13 N-ammonia were included in the study. PET was considered positive when &gt;1 contiguous segments showed both stress MBF ≤2.3 mL/g/min and MFR ≤2.5 for 15 O-water or ≤1.79 mL/g/min and ≤2.0, for 13 N-ammonia respectively. A vFAI threshold of 0.85 was used as predictor of impaired vasodilating capability. ESS computation was based on a mean aortic pressure of 100 mmHg for the inlet and a mean blood flow at rest of 0.00105 kg/s for the outlet. ESS was calculated (Pa) in the full length of the stenosis and the mean value was obtained. Results Hybrid imaging analysis was performed in CTCA and PET datasets. 51 coronary segments were assessed. There were 27 lesions with stenosis 31–50% and 24 lesions with stenosis 51–70%. ESS was higher in the latter (20.4, IQ: 11.4–32.1 vs. 10.4, IQ: 5.5–15.7, p=0.04). Similarly, ESS was higher in stenoses with impaired vasodilating capacity compared to those without, although this difference did not reach statistical significance (22.8, IQ: 13.2–35.1 vs. 10.6, IQ: 5.7–22.1, p=0.10). The ROC curve analysis for prediction of both abnormal stress MBF and MFR followed the same pattern (AUC=0.668, 95% confidence interval (CI): 0.490–0.810, p=0.11).On the other hand, there was a moderate negative correlation (r=−0.41, p=0.004) between ESS and vFAI and the former was lower in stenoses with vFAI &gt;0.85 compared to those below this threshold (7.35, IQ: 3.2–13.9 vs. 19.1, IQ: 14.1–32.8, p=0.012). vFAI was a good predictor of coronary flow capacity (AUC=0.737, CI: 0.58–0.85, p=0.02). Conclusion Calculation of ESS is feasible in CTCA datasets. ESS was related with stenosis severity and there was a trend to be higher in lesions with impaired coronary vasodilating capability. ESS is modestly related with vFAI and may also be an additional predictor of impaired regional myocardial flow obtained by PET imaging. Acknowledgement/Funding This study has received funding from the EU H2020 research and innovation programme under grant agreement No 689068 and from p-Med GR 5002802

P927Long-term mortality in patients with paradoxical low-flow low-gradient versus normal-flow high-gradient aortic stenosis undergoing transcatheter aortic valve implantation

Abstract Background Controversial data exist on clinical outcomes of patients with paradoxical low-flow, low-gradient aortic stenosis (PLF-LG) undergoing valve replacement. This entity is a combination of a small aortic valve area (AVA&lt;1cm2), a preserved left ventricular ejection fraction (LVEF≥50%), and a “paradoxical” low mean gradient due to the presence of low LV stroke volume (≤35 mL/m2). The low flow state is explained by the presence of a high afterload and pronounced LV concentric remodeling, with impaired LV filling. Currently, poorer outcomes have been reported after surgical aortic valve replacement in patients with PLF-LG AS compared with the normal-flow high-gradient (NF-HG) AS. Purpose The aim of this study was to determine the clinical outcomes in patients with PLF-LG AS undergoing transcatheter aortic valve implantation (TAVI) compare to NF-HG patients. Methods A total of 609 patients (age 81±6 years) with symptomatic severe AS and preserved LVEF who underwent TAVI, was enrolled and divided in two groups: group A included patients with NF-HG (542 patients) and group B including those with PLF-LG (66 patients). At 1-year follow-up, death and clinical events were reported. Results TAVI was feasible in all patients. A significant reduction in mean aortic pressure gradient was observed after TAVI both in PLF-LG (baseline, 30±5 mmHg; 1-year, 11±4 mmHg; p&lt;0.001) and in NF-HG (baseline, 53±11 mmHg; 1-year, 12±4 mmHg; p&lt;0.001) together with an increase in AVA (PLF-LG: baseline, 0.74±0.16 cm2, 1-year: 1.83±0.41 cm2, p&lt;0.001; NF-HG: baseline, 0.65±0.16 cm2, 1-year: 1.84±0.35cm2, p&lt;0.001). Perioperative mortality at 30-days was similar in group A (17/542, 3%) and in group B (2/66, 3%). Figure shows the survival curves up to 5 years follow-up according to the two groups. PLF-LG and HG-AS had similar survival rate throughout the long-term follow-up. Similarly, rehospitalization rate was not different in the two groups (PLF-LG: 12% vs NF-HG: 7%, p=0.121). Kaplan-Meier analysis Conclusions Differently from surgical series, TAVI patients with PLF-LG AS had showed similar mortality and rehospitalization rates compared to NF-HG.

P908Prognostic value of energy loss index in patients with low gradient severe aortic stenosis and preserved ejection fraction

Abstract Background Assessment of pressure recovery adjusted indexed aortic valve area (AVAi) – energy loss index (ELI) – has been shown of prognostic interest for patients with asymptomatic and/or mild aortic stenosis (AS), but limited data are available in the setting of low gradient aortic stenosis (LG-AS). Purpose We hypothesized that among these patients with LG-AS, reclassification of AS severity as moderate by ELI may help to identify a subgroup of patients with moderate AS. Methods 379 patients with low gradient severe AS (defined by AVAi ≤0.6 cm2/m2 and mean aortic pressure gradient (MPG) &lt;40 mmHg) and preserved left ventricular ejection fraction (LVEF ≥50%) were prospectively included. Reclassification as moderate AS by ELI was defined as AVAi ≤0.6 cm2 /m2 but an ELI &gt;0.6 cm2/m2. Clinical and echocardiographic features of patients reclassified by ELI were studied. Clinical outcomes were all-cause and cardiac mortality. Results 148 patients (39%) were reclassified as moderate AS by ELI. By multivariable logistic regression analysis, patients being reclassified as moderate AS by ELI were associated with increased stroke volume index (SVi), absence of documented coronary artery disease and decreased body surface area, left indexed ventricular mass (all p&lt;0.05). During a median follow-up of 34 months (30–38 months), 119 patients died, 52 of them from cardiac causes. Three-year survival free from all-cause or cardiac death were 76±4%, 96±2% for patients with moderate AS by ELI and 71±3%, 84±3% for patients with severe AS by ELI (p=0.178 and p=0.013, respectively). After adjustment for variables of prognostic interest including aortic valve replacement as a time-dependent covariable, there was a significant reduction of risk of cardiac mortality in patients with moderate AS by ELI (adjusted HR 0.44 [95% CI, 0.23–0.85]; p=0.014) but not for all-cause mortality (adjusted HR 0.85 [95% CI, 0.58–1.25]; p=0.403) Conclusion In patients with low gradient “severe” AS and preserved ejection fraction, calculation of ELI permits to reclassify almost 40% of patients as having moderate AS. Patients reclassified as moderate AS by ELI had a reduction of risk of cardiac mortality during follow-up but not for all-cause mortality. Calculation of ELI may be useful for decision making in AS patients with discordant grading and preserved ejection fraction. Acknowledgement/Funding Local funding