Low-dose Dobutamine Stress Echocardiography Research Articles

P357 DOES CARDIAC AMYLOIDOSIS EVER HIDE A SEVERE AORTIC STENOSIS A CASE REPORT

Abstract Case presentation: A 89-year-old man, with an history of paroxysmal atrial fibrillation and chronic renal disease, was admitted to our ER for acute decompensated heart failure. He reported dyspnea on minimal exertion and worsening peripheral edema. He had a history of heart failure and a severe aortic stenosis first diagnosed in 2020 with an echocardiogram demonstrating a left ventricular ejection fraction (LVEF) of 30% and a low-flow low-gradient aortic stenosis (AVA=0,6 cmq, mean pressure gradient=21 mmHg). Besides, in 2019, he underwent a 99m Tc MDP scintigraphy for a prostatic nodule which showed important myocardial uptake of the bone tracer highly suggestive of cardiac amyloidosis. Urinary light chain assessment and determination of immunoglobulin light chain levels were negative for AL amyloidosis. The electrocardiogram showed: sinus rhythm, low voltage in the frontal leads and complete left bundle branch block with secondary repolarization abnormalities. The patient underwent transthoracic echocardiography for staging the severity of the aortic valve stenosis, which revealed borderline results: the aortic valve area was 0.5 cmq with a transaortic mean pressure gradient of 20 mmHg (EF 25%, with GLS of −5%). Low-dose dobutamine stress echocardiography was performed. At rest conditions, there was global hypokinesia with an ejection fraction of 24%. Aortic valve mean pressure was 19 mmHg referring to a calculated aortic valve opening area of 0,78 cmq. Under peak dobutamine stress (30 mcg/kg/min), LVEF increased to 36%. On the basis of these diagnostic findings, aortic stenosis was classified as pseudo-severe due to systolic dysfunction of the left ventricle with preserved contractile reserve. Besides, aortic calcium score of 574 confirmed that the aortic stenosis was non severe. Conclusions This case results exemplary of the fact that amyloidosis does not always hide a severe stenosis. Actually the echo with dobutamine indicates a non-valvular reason for heart-failure and no indication for valve replacement.The discharge suggestions consists of clinical/ echo follow ups and TTR stabilizers. Anyway, Tafamidis is not recommended because of the age and the patient short life expectancy. The implantation of CCM which, during the action potential platea delivers non-excitatory electrical currents and enhances systolic function in patients with heart failure, is proposed to obtain an improvement of symptoms.

ABCDEG Stress Echocardiography in Aortic Stenosis.

Rest and stress echocardiography (SE) plays a pivotal role in the evaluation of valvular heart disease. The use of SE is recommended in valvular heart disease when there is a mismatch between resting transthoracic echocardiography findings and symptoms. In aortic stenosis (AS), rest echocardiographic analysis is a stepwise approach that begins with the evaluation of aortic valve morphology and proceeds to the measurement of the transvalvular aortic gradient and aortic valve area (AVA) using continuity equations or planimetry. The presence of the following three criteria suggests severe AS: AVA < 1.0 cm2, a peak velocity > 4.0 m/s, or a mean gradient > 40 mmHg. However, in approximately one in three cases, we can observe a discordant AVA < 1 cm2 with a peak velocity < 4.0 m/s or a mean gradient <40 mmHg. This is due to reduced transvalvular flow associated with LV systolic dysfunction (LVEF < 50%) defined as "classical" low-flow low-gradient (LFLG) AS or normal LVEF "paradoxical" LFLG AS. SE has an established role in evaluating LV contractile reserve (CR) patients with reduced LVEF. In classical LFLG AS, LV CR distinguished pseudo-severe AS from truly severe AS. Some observational data suggest that long-term prognosis in asymptomatic severe AS may not be as favorable as previously thought, offering a window of opportunity for intervention prior to the onset of symptoms. Therefore, guidelines recommend evaluating asymptomatic AS with exercise stress in physically active patients, particularly those younger than 70 years, and symptomatic classical LFLG severe AS with low-dose dobutamine SE. A comprehensive SE assessment includes evaluating valve function (gradients), the global systolic function of the LV, and pulmonary congestion. This assessment integrates considerations of blood pressure response, chronotropic reserve, and symptoms. StressEcho 2030 is a prospective, large-scale study that employs a comprehensive protocol (ABCDEG) to analyze the clinical and echocardiographic phenotypes of AS, capturing various vulnerability sources which support stress echo-driven treatment strategies.

Value of Speckle Tracking Echocardiography Combined with Stress Echocardiography in Predicting Surgical Outcome of Severe Aortic Regurgitation with Markedly Reduced Left Ventricular Function

Background: Predicting outcomes of surgical aortic valve replacement (AVR) in patients with chronic severe aortic regurgitation (AR) and markedly reduced left ventricular (LV) function remains a challenge. This study aimed to explore the preoperative echocardiographic index that could predict the recovery of LV systolic function after surgery in patients with chronic severe AR and reduced left ventricular ejection fraction (LVEF). Methods: The study group consisted of 50 patients diagnosed with chronic severe AR (&gt;6 months) and significantly reduced LVEF (18~35%, average 26.2 ± 5.3%). Low-dose dobutamine stress echocardiography (DSE) was performed before surgery. Only patients with an absolute increase in LVEF ≥8% during DSE were referred for surgical AVR. During following up (over six months to one year after surgery), the patients were divided into two groups by postoperative LVEF (&gt; or ≤40%). DSE- and speckle tracking echocardiography (STE)-derived LV functional parameters were compared between groups to identify predictors of post-operative improvement in LVEF. Results: A total of 38 patients underwent AVR. One patient died before discharge. Post-surgical LV size and LVEF improved markedly after surgery in all patients (n = 37). Pre-surgical LV end-systolic diameter, baseline global longitudinal strain (GLS) and peak GLS were better in the group with LVEF &gt;40% (n = 18; p &lt; 0.05, t test). Baseline GLS and peak GLS correlated moderately with post-surgery LVEF (R = –0.581, p &lt; 0.001; R = –0.596, p &lt; 0.001; respectively). Logistic regression analysis demonstrated baseline GLS and peak GLS were the independent predictors of post-surgery improvement of LVEF. Peak GLS had the highest prediction value (area under the curve = 0.895, sensitivity and specificity: 89.5% and 77.8%, respectively), with a cutoff value of –9.4%. Conclusions: This study shows that STE combined with DSE can provide sensitive quantitative indices for predicting improvement of LV systolic function after AVR in patients with chronic severe AR and significantly decreased LVEF.

Childhood Cancer Survivors Have Impaired Strain-Derived Myocardial Contractile Reserve by Dobutamine Stress Echocardiography.

Abnormal left ventricular contractile reserve (LVCR) is associated with adverse cardiac outcomes in different patient cohorts and might be useful in the detection of cardiomyopathy in childhood cancer survivors (CCS) after cardiotoxic treatment. The aim of this study was to evaluate LVCR by dobutamine stress echocardiography (DSE) combined with measures of myocardial strain in CCS previously treated with anthracyclines (AC). Fifty-three CCS (age 25.34 ± 2.44 years, 35 male) and 53 healthy controls (age 24.40 ± 2.40 years, 32 male) were included. Subjects were examined with echocardiography at rest, at low-dose (5 micrograms/kg/min), and at high-dose (40 micrograms/kg/min) dobutamine infusion. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS), strain rate (GSR), and early diastolic strain rate (GEDSR) at different DSE phases were used as measures of LVCR. The mean follow-up time among CCS was 15.8 ± 5.8 years. GLS, GSR, and LVEF were lower at rest in CCS compared to controls (p ≤ 0.03). LVEF was within the normal range in CCS. ΔGLS, ΔGSR, and ΔGEDSR but not ΔLVEF were lower in CCS compared to controls after both low- (p ≤ 0.048) and high-dose dobutamine infusion (p ≤ 0.023). We conclude that strain measures during low-dose DSE detect impaired myocardial contractile reserve in young CCS treated with AC at 15-year follow-up. Thus, DSE may help identify asymptomatic CCS at risk for heart failure and allows for tailored follow-up accordingly.

Dobutamine stress echocardiography during transcatheter edge-to-edge mitral valve repair predicts residual mitral regurgitation.

The current study sought to determine whether low-dose dobutamine stress echocardiography (DSE) during transcatheter edge-to-edge mitral valve repair (TMVR) can predict residual mitral regurgitation (MR) at discharge. In most patients, TMVR can successfully reduce MR from severe to mild or moderate. However, general anesthesia during the intervention affects hemodynamics and MR assessment. At discharge transthoracic echocardiogram residual MR (>moderate) is present in 10%-30% of patients which is associated with worse clinical outcome. In consecutive patients the severity of MR was determined at baseline, immediately after TMVR clip implantation and subsequently during low-dose DSE (both under general anesthesia) and at discharge. A total of 39 patients were included (mean age 76.1 ± 8.1 years, 39% male, 56% functional MR, 41% left ventricular ejection fraction < 45%). An increase of MR during DSE was seen in 11 patients, of whom 6 (55%) showed >moderate MR at discharge. None of the 28 patients without an increase of MR during DSE showed >moderate MR at discharge. The diagnostic performance of the test could be established at a sensitivity of 100% and a specificity of 85% in unselected patients. DSE during TMVR is a useful tool to predict residual MR at discharge. It could support procedural decision making, including implantation of additional clips and thus potentially improve clinical outcome.

Влияние миокардиального станнинга на динамику показателей митральной регургитации и ремоделирования после перенесенного инфаркта миокарда

Aim. To study the dynamics of mitral regurgitation depending on the results of low dose dobutaminestress-echocardiography with effectiveness of myocardial reperfusion and in patients after MI with STsegment elevation.Material and methods. The study included 302 patients with STeMI. All patients underwent myocardialreperfusion. Depending on the effectiveness of reperfusion, the patients were divided into 3 groups: group1 – 196 (65%) patients with successful reperfusion; group 2 – 76 (25%) patients with partial reperfusion,group 3 – 30 (10%) patients with no reperfusion. The indicators of systolic function, LV remodeling, mitralregurgitation at rest, under pharmacological load and after a month were studied. To determine the zoneof viable myocardium, stress echocardiography with low doses of dobutamine was used.Results. Indicators characterizing the severity of MR had a negative trend in patients of group 3, who showedan increase in ERO, PISA and vena contracta width. But in patients of the 1st and 2nd groups with the presence of myocardial stunning, an unreliable decrease in these indicators of the degree of MR was noted. Identification of viable zones by low-dose dobutamine stress echocardiography in areas of LV dysfunction preventsthe progression of MR and serious intracardiac hemodynamic disturbances and will also be reversible.Conclusion. The main mechanism in the progression of MR in patients after AMI is LV myocardial dysfunction with further LV remodeling accompanied by dilatation and spherification of its cavity. The presenceof a viable myocardium in the zone of dysfunction can prevent the progression of MR, and even lead toa decrease in its degree with adequate revascularization. Patients with MR, with a lack of viability in thearea of myocardial dysfunction, are candidates for the development of severe MI.

The evaluation of coronary microvascular obstruction in patients with STEMI by cardiac magnetic resonance T2-STIR image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography.

This study was designed to assess coronary microvascular obstruction (MVO) in patients with acute ST-segment elevation myocardial infarction (STEMI) by cardiac magnetic resonance T2-weighted short tau inversion recovery (T2-STIR) image and layer-specific analysis of 2-dimensional speckle tracking echocardiography combined with low-dose dobutamine stress echocardiography (LDDSE-LS2D-STE). 32 patients were enrolled to perform cardiac magnetic resonance and echocardiography 5-7days after primary percutaneous coronary intervention. Infarcted myocardium was categorized into MVO+ group and MVO- group by late gadolinium enhancement as gold standard. At T2-weighted image, the area of hyper-intense region and hypo-intense core inside were marked as A1, A2 and A2/A1 > 0 represented MVO. Strain parameters were composed of longitudinal strain (LS), circumferential strain and radial strain at rest and dobutamine stress. There were 94 MVO+ segments, 136 MVO- segments according to gold standard. 96 segments had hypo-intense core at T2-STIR image. The sensitivity and specificity of T2-STIR in detecting MVO were 91.49 and 92.65%. Endocardial LS was superior to other parameters, and stress endocardial LS was higher than that of resting endocardial LS (sensitivity: 77.11% vs 72.29%, specificity: 93.28% vs 83.19%, AUC: 0.87 vs 0.82, P < 0.05). The combination of T2-STIR and stress endocardial LS in parallel test could improve sensitivity significantly (98.05% vs 91.49%). T2-STIR has higher diagnostic value in detecting MVO with some limitations. However, LDDSE-LS2D-STE with cost-effective and handling may be a good alternative to T2-STIR. It provides additional and reliable diagnostic tools to identify MVO in STEMI patients after reperfusion.

Comparison of Diagnostic Value Between STE+LDDSE and CMR-FT for Evaluating Coronary Microvascular Obstruction in Post-PCI Patients for STEMI.

BackgroundCoronary microvascular obstruction (CMVO) is closely associated with poor prognosis of ST-segment elevation myocardial infarction (STEMI) patients. However, data showing the comparison between cardiac magnetic resonance feature tracking (CMR-FT) and speckle tracking echocardiography (STE) combined with low-dose dobutamine stress echocardiography (LDDSE) in evaluating CMVO was scarcely available. We aimed to explore and compare the predictive value between CMR-FT and STE+LDDSE in detecting CMVO.MethodsSixty-one STEMI patients were executed cardiac magnetic resonance and echocardiography within the first 5–7 days after primary percutaneous coronary intervention (PCI). The myocardial strain analysis was performed in STE, STE+LDDSE, and CMR-FT, and strain parameters included radial strain (RS), circumferential strain (CS), and longitudinal strain (LS). ROC curves were performed to predict infarcted myocardium segments with CMVO.ResultsFinally, 324 infarcted myocardium segments were analyzed, including 100 infarcted segments with CMVO and 224 segments without CMVO by the gold standard assessment of late gadolinium-enhancement cardiac magnetic resonance imaging (LGE-CMR). The results showed that CS was generally superior to RS and LS in identifying CMVO. CS in CMR-FT facilitated the detection of CMVO, with a sensitivity, specificity, and accuracy of 78.00%, 81.25%, and 80.25%, respectively. The sensitivity, specificity, and accuracy of CS in STE combined with LDDSE were better than STE alone (76.00% vs 60.00%, 79.91% vs 64.29%, and 78.70% vs 62.96%, P < 0.05). In addition, CMR-FT is not superior to STE+LDDSE for detection of CMVO (P > 0.05).ConclusionLow-dose dobutamine can improve the clinical value of STE for evaluating CMVO in STEMI patients. Compared with CMR-FT, STE+LDDSE might be a better choice for STEMI patients because of its safety, convenience, and low-cost.

Dynamics of the Indicators of Low Dose Dobutamine Stress-Echocardiography under the Influence of High Doses of Atorvastatin in Patients with ST Elevation Myocardial Infarction

The aim of investigation: to study the effect of early administration high doses of atorvastatin in the acute period of STEMI on the indicators of low dose dobutamine stress-echocardiography and parameters of left ventricular remodeling. Material and Methods: The study included 164 patients with STEMI All patients underwent myocardial revascularization (TLT or PCI) within the first 6 hours. The 1st group included 82 patients who received basic therapy (atorvastatin 20 mg), the 2nd group included 82 patients who took a loading dose of atorvastatin (at a dose of 80 mg per day). Low dose dobutamine stress-echocardiography was performed to detect myocardial stunning after stabilization of the patients condition on 4–6 days of the disease. In addition to general clinical and conventional laboratory research methods, on the 1st day and on the 10th day of treatment, the level of CPK MB, ESR, the number of blood leukocytes, and the level of fibrinogen (FN) were determined. Results: On the 10th day of therapy in patients of both groups, there was a significant increase in ESR (in the 1st group by 2.1 times, in the 2nd - by 1.6 times) and a decrease in the level of CRP (by 3 and 2.65 times, respectively) compared to the first day. The dynamics of these indicators reflects the regular processes of the course of AMI. A more significant change in these parameters was recorded in patients of the 2nd group who took atorvastatin at a dose of 80 mg. At the same time, on the 10th day of AMI, the number of peripheral blood leukocytes significantly decreased in them (p&lt;0.05 when compared between groups). The number of dobutamine-responsive segments (segments with reversible dysfunction) in the group of patients treated with atorvastatin at a dose of 80 mg during myocardial reperfusion was significantly higher than in the control group (p&lt;0.05). Conclusion: It was revealed that conducting of myocardium reperfusion in infarct-related coronary artery with simultaneous use of atorvastatin’s high doses promoted the limitation of myocardial necrosis development, reducing ischemic and reperfusion injuries of myocardium and influenced on the formation of myocardial stunning zones which is a reversible disfunction. The use of atorvastatin in the dose of 80 mg/per day in the first hours after acute myocardial infarction development promotes the improvement of LV systolic indices, prevents the progressing of LV cavity postinfarction dilatation.

The effect of empagliflozin on contractile reserve in heart failure: Prespecified sub-study of a randomized, double-blind, and placebo-controlled trial

Sodium-glucose co-transporter-2 inhibitors improve cardiac structure but most studies suggest no change in left ventricular (LV) systolic function at rest. Whether sodium-glucose co-transporter-2 inhibitors improve LV contractile reserve is unknown. We investigated the effect of empagliflozin on LV contractile reserve in patients with heart failure (HF) and reduced ejection fraction. Prespecified sub-study of the Empire HF trial, a double-blind, placebo-controlled, and randomized trial. Patients with LV ejection fraction (LVEF) ≤ 40% on guideline-directed HF therapy were randomized (1:1) to empagliflozin 10 mg or placebo for 12 weeks. The treatment effect on contractile reserve was assessed by low dose dobutamine stress echocardiography. In total, 120 patients were included. The mean age was 68 (SD 10) years, 83% were male, and the mean LVEF was 38 (SD 10) %. Respectively 60 (100%) and 59 (98%) patients in the empagliflozin and placebo groups completed stress echocardiography. No statistically significant effect of empagliflozin was observed for the contractile reserve assessed by LV-GLS (adjusted mean absolute change, empagliflozin vs placebo, 0.7% [95% confidence interval {CI} -0.5 to 2.0, P=.25]) or LVEF (adjusted mean absolute change, empagliflozin vs placebo, 2.2% [95% CI -1.4 to 5.8, P=.22]) from baseline to 12 weeks. LV-GLS contractile reserve was associated with accelerometer-measured daily activity level (coefficient -24 accelerometer counts [95% CI -46 to -1.8, P=.03]). Empagliflozin for 12 weeks added to guideline-directed HF therapy did not improve LV contractile reserve in patients with HF and reduced ejection fraction.

Utility of dobutamine stress echocardiography in aortic valve regurgitation and reduced left ventricular function.

Predictors for post-operative reverse remodeling in patients with severe aortic regurgitation (AR) and reduced left ventricular ejection fraction (LVEF) are unknown. We performed low-dose dobutamine stress echocardiography (DSE) in patients with severe AR and reduced LVEF to evaluate the relationship between contractile reserve (CR) and reverse remodeling after surgery. In 31 patients with chronic severe AR and reduced LVEF (LVEF<50%), we performed pre-operative DSE, assessed CR, and examined whether changes in preoperative DSE were associated with improvement of post-operative LVEF after aortic valve surgery. The pre-operative echocardiographic findings were as follows: left ventricular (LV) end-diastolic dimension: 67 ± 10mm, LV end-systolic dimension: 52 ± 13mm, and LVEF: 42 ± 8%. All patients underwent aortic valve surgery. Patients with pre-operative LVEF of ≥45% exhibited a significant increase in LVEF; however, patients with pre-operative LVEF of <45% showed no significant change. When we examined the results of DSE performed in patients with pre-operative LVEF of <45%, ΔLVEF of ≥6% (with CR) during DSE was related to an improvement in post-operative LVEF; ΔLVEF of ≥6% during DSE predicted an improvement in post-operative LVEF, with sensitivity 100%; specificity 78%; and area under curve (AUC) .92. DSE might be a helpful tool for predicting post-operative reverse remodeling in patients with severe AR and moderately reduced LVEF.

Abstract 13062: The Effect of Empagliflozin on Contractile Reserve in Heart Failure: Prespecified Sub-Study of a Randomized, Double-Blind, and Placebo-Controlled Trial

Introduction: Sodium-glucose co-transporter-2 (SGLT2) inhibitors improve cardiac structure but most studies suggest no change in left ventricular (LV) systolic function at rest. Whether SGLT2 inhibitors improve LV contractile reserve is unknown. We investigated the effect of empagliflozin on LV contractile reserve in patients with heart failure (HF) and reduced ejection fraction (HFrEF). Methods: Prespecified sub-study of the Empire HF trial, a double-blind, placebo-controlled, and randomized trial. Patients with LV ejection fraction (LVEF) ≤40% on guideline-directed HF therapy were randomized (1:1) to empagliflozin 10 mg or placebo for 12 weeks. The treatment effect on contractile reserve was assessed by low dose dobutamine stress echocardiography. Results: In total, 120 patients were included. The mean age was 68 (SD 10) years, 83% were male, and the mean LVEF was 38 (SD 10) %. Respectively 60 (100%) and 59 (98%) patients in the empagliflozin and placebo groups completed stress echocardiography. No statistically significant effect of empagliflozin was observed for the contractile reserve assessed by LV-GLS [adjusted mean absolute change, empagliflozin versus placebo, 0.7% (95% CI -0.5 to 2.0, P=0.25)] or LVEF [adjusted mean absolute change, empagliflozin versus placebo, 2.2% (95% CI -1.4 to 5.8, P=0.22)] from baseline to 12 weeks. LV-GLS contractile reserve was associated with accelerometer-measured daily activity level [coefficient, -24 accelerometer counts (95% CI -46 to -1.8, P=0.03)] as opposed to LVEF contractile reserve [coefficient, -2.9 accelerometer counts (95% CI -10 to 4.5, P=0.43)]. Conclusions: Empagliflozin for 12 weeks added to guideline-directed HF therapy did not improve LV contractile reserve in patients with HFrEF. Registration: NCT03198585. https://www.clinicaltrials.gov/ct2/show/NCT03198585?term=Empire+HF&amp;draw=2&amp;rank=1

Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography.

In acute ST-segment elevation myocardial infarction (STEMI) late gadolinium enhancement (LGE) may underestimate segmental functional recovery. We evaluated the predictive value of cardiac magnetic resonance (CMR) feature-tracking (FT) for functional recovery and whether it incremented the value of LGE compared to low-dose dobutamine stress echocardiography (LDDSE) and speckle-tracking echocardiography (STE). Eighty patients underwent LDDSE and CMR within 5–7 days after STEMI and segmental functional recovery was defined as improvement in wall-motion at 6-months CMR. Optimal conventional and FT parameters were analyzed and then also applied to an external validation cohort of 222 STEMI patients. Circumferential strain (CS) was the strongest CMR-FT predictor and addition to LGE increased the overall accuracy to 74% and was especially relevant in segments with 50–74% LGE (AUC 0.60 vs. 0.75, p = 0.001). LDDSE increased the overall accuracy to 71%, and in the 50–74% LGE subgroup improved the AUC from 0.60 to 0.69 (p = 0.039). LGE + CS showed similar value as LGE + LDDSE. In the validation cohort, CS was also the strongest CMR-FT predictor of recovery and addition of CS to LGE improved overall accuracy to 73% although this difference was not significant (AUC 0.69, p = 0.44). Conclusion: CS is the strongest CMR-FT predictor of segmental functional recovery after STEMI. Its incremental value to LGE is comparable to that of LDDSE whilst avoiding an inotropic stress agent. CS is especially relevant in segments with 50–74% LGE where accuracy is lower and further testing is frequently required to clarify the potential for recovery.

Clinical Value of Stress Transaortic Flow Rate During Dobutamine Echocardiography in Reduced Left Ventricular Ejection Fraction, Low-Gradient Aortic Stenosis: A Multicenter Study.

Low rest transaortic flow rate (FR) has been shown previously to predict mortality in low-gradient aortic stenosis. However limited prognostic data exists on stress FR during low-dose dobutamine stress echocardiography. We aimed to assess the value of stress FR for the detection of aortic valve stenosis (AS) severity and the prediction of mortality. This is a multicenter cohort study of patients with reduced left ventricular ejection fraction and low-gradient aortic stenosis (aortic valve area <1 cm2 and mean gradient <40 mm Hg) who underwent low-dose dobutamine stress echocardiography to identify the AS severity and presence of flow reserve. The outcome assessed was all-cause mortality. Of the 287 patients (mean age, 75±10 years; males, 71%; left ventricular ejection fraction, 31±10%) over a mean follow-up of 24±30 months there were 127 (44.3%) deaths and 147 (51.2%) patients underwent aortic valve intervention. Higher stress FR was independently associated with reduced risk of mortality (hazard ratio, 0.97 [95% CI, 0.94-0.99]; P=0.01) after adjusting for age, chronic kidney disease, heart failure symptoms, aortic valve intervention, and rest left ventricular ejection fraction. The minimum cutoff for prediction of mortality was stress FR 210 mL/s. Following adjustment to the same important clinical and echocardiographic parameters, among the three criteria of AS severity during stress, ie, the guideline definition of aortic valve area <1cm2 and aortic valve mean gradient ≥40 mm Hg, or aortic valve mean gradient ≥40 mm Hg, or the novel definition of aortic valve area <1 cm2 at stress FR ≥210 mL/s, only the latter was independently associated with mortality (hazard ratio, 1.72 [95% CI, 1.05-2.82]; P=0.03). Furthermore aortic valve area <1cm2 at stress FR ≥210 mL/s was the only severe aortic stenosis criterion that was associated with improved outcome following aortic valve intervention (P<0.001). Guideline-defined stroke volume flow reserve did not predict mortality. Stress FR during low-dose dobutamine stress echocardiography was useful for the detection of both AS severity and flow reserve and was associated with improved prediction of outcome following aortic valve intervention.

Low-Dose Dobutamine Stress Echocardiography for the Early Detection of Pulmonary Arterial Hypertension in Selected Patients with Systemic Sclerosis Whose Resting Echocardiography Is Non-Diagnostic for Pulmonary Hypertension.

Background: Dobutamine stress echocardiography (DSE) has limited application in systemic sclerosis (SSc). We examined DSE usefulness in revealing pulmonary arterial hypertension (PAH) in selected SSc patients whose resting echocardiography for pulmonary hypertension (PH) was non-diagnostic. Methods: Forty SSc patients underwent right heart catheterization (RHC) and, simultaneously, low-dose DSE (incremental doses up to 20 μg/kg/min). Inclusion criteria were: preserved left and right ventricular (RV) function (tricuspid annulus plane systolic excursion [TAPSE] ≥ 16 mm and tissue Doppler imaging-derived systolic velocity of tricuspid annulus [RVS’] > 10 cm/s), normal pulmonary function tests, and baseline maximal tricuspid regurgitation (TR) velocity of 2.7–3.2 m/s. Results: Of 36 patients who completed DSE, resting RHC diagnosed PAH in 12 patients (33.3%). At 20 μg/kg/min, patients with PAH had higher TR velocity, higher pulmonary arterial pressure measured by RHC, and lower RV inotropic response compared with patients without PAH. A cut-off value of maximal TR velocity >3.1 m/s had a sensitivity of 80%, a specificity of 84.2%, and an accuracy of 82.4% for the detection of PAH. Conclusions: Low-dose DSE has a satisfactory diagnostic accuracy for the early detection of PAH in highly selected SSc patients whose baseline echocardiographic measurements for PH lie in the gray zone.

Predictors of true-severe classical low-flow low-gradient aortic stenosis at resting echocardiography

BackgroundClassical low-flow, low-gradient (LF/LG) aortic stenosis (AS) is subclassified into a true-severe (TS) and a pseudo-severe (PS) subform using low-dose dobutamine stress echocardiography (DSE). In clinical practice a resting peak jet velocity (Vmax) >3.5 m/s or a mean transvalvular gradient (MPG) >35 mmHg suggests the presence of TS classical LF/LG AS, but there is no data to support this. The aim of this study was therefore to investigate whether a resting Vmax >3.5 m/s or MPG >35 mmHg reliably predicted diagnosis of TS classical LF/LG AS. MethodsOne hundred (100) consecutive patients with classical LF/LG AS were prospectively recruited. All patients underwent DSE for subcategorization. The impact of Vmax and MPG for the presence of the TS subform were analyzed. ResultsTS classical LF/LG AS was diagnosed in 72 patients. Resting Vmax and resting MPG predicted true-severity with an ROC-AUC of 0.737 (95%CI: 0.635–0.838; p < 0.001) and 0.725 (95%CI: 0.615–0.834; p < 0.001), respectively. The optimal positive predictive values (PPV) for the diagnosis of TS classical LF/LG AS were obtained with a resting Vmax >3.5 m/s or resting MPG >35 mmHg. In a multivariate logistic regression analysis, Vmax >3.5 m/s was independently associated with a 5.33-fold odds-ratio of TS classical LF/LG AS (OR 5.33; 95%CI: 1.34–21.18, p = 0.018). ConclusionsTS classical LF/LG AS can be reliably predicted by a resting Vmax >3.5 m/s or a resting MPG >35 mmHg. Further imaging for subclassification is not needed in this situation.

Clinical value of stress transaortic flow rate during dobutamine echocardiography in low-gradient aortic stenosis

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND/INTRODUCTION The clinical value of rest transaortic flow rate (FR) has been shown previously in low-gradient aortic stenosis (LGAS) for the prediction of outcome. However limited data exists on the prognostic value of stress FR in LGAS following low-dose dobutamine stress echocardiography (LDDSE). PURPOSE We aimed to assess the value of stress FR in patients with LGAS in the diagnosis of AS severity and the prediction of mortality. METHODS This is a multi-centre cohort study of patients with low left ventricular ejection fraction (LVEF) and LGAS (aortic valve area –AVA &amp;lt;1cm²) who underwent LDDSE. RESULTS Of the 287 patients (mean age: 75.1 ±10 years, males: 71%) over the mean follow-up of 24 ±30 months there were 127 (44.3%) deaths and 147 (51.2%) patients underwent aortic valve intervention. Lower stress FR was independently associated with increased risk of mortality (HR= 0.99, 95%CI= 0.99-0.999, p= 0.02) after adjusting for age, chronic kidney disease, presence of symptoms (NYHA II-IV), aortic valve intervention, rest LVEF and guideline-defined severe AS (AV mean gradient- AVMG ≥40mmHg with AVA &amp;lt;1cm² at peak stress). The minimum cut-off for prediction of mortality was stress FR 210ml/sec. Among the different criteria of AS severity during stress, i.e. guideline-defined criterion, or stress AVMG ≥40mmHg, or stress AVA &amp;lt;1cm² at stress FR ≥210ml/s, only the latter was independently associated with mortality (HR= 1.81, 95%CI= 1.04-3.2, p= 0.04) (Table 1) and was the parameter of AS severity that predicted improved outcome following aortic valve intervention (p &amp;lt;0.005) (Figure 1). Guideline-defined stroke volume flow reserve did not predict mortality. CONCLUSIONS Assessment of stress FR during LDDSE is important for the detection of both AS severity and flow reserve. Table 1 Multivariable analysis for prediction of all-cause mortality (N = 287) for the different criteria of aortic stenosis HR 95%CI p Age 1 0.98-1.03 0.84 Chronic kidney disease 1..84 1.13-2.99 0.01 Aortic valve intervention 0.37 0.22-0.61 &amp;lt;0.005 Presence of symptoms (NYHA II-IV) 1.87 0.66-5.31 0.24 Rest LVEF (by 1%) increase 0.97 0.95-1 0.06 Stress AVA &amp;lt; 1cm&amp;sup2; with stress AVMG≥40mmHg 1.02 0.31-3.34 0.97 Stress AVMG≥40mmHg 0.57 0.2-1.59 0.28 Stress AVA &amp;lt; 1cm&amp;sup2; at stress FR≥210mmHg 1.81 1.04-3.2 0.04 Abstract Figure 1

IMPACT OF TIME ON SHORT TERM OUTCOME FOR PERCUTANEOUS CORONARY INTERVENTION AFTER FAILED FIBRINOLYSIS FOR STEMI PATIENTS

Background: Although primary percutaneous coronary intervention (PPCI) is the most preferred reperfusion strategy for ST-segment-elevation in myocardial infarction (STEMI), fibrinolytic therapy is considered a valid alternative when PPCI is not feasible or cannot be done within 1 hour after the first medical contact. Objective: To assess the short-term outcome of anterior STEMI patients after failed fibrinolytic therapy, undergoing rescue PCI at 3 different timing scenarios, and to study the effect of delayed intervention on the outcome. Patients and Methods: This study included 63 patients with a diagnosis of anterior STEMI admitted to CCU in Nasser Institute hospital and Sayed Galal University Hospital from December 2016 to August 2018. They received thrombolysis by using streptokinase (1.500.000 IU) without clinical and/or electrocardiographic evidence of successful reperfusion within 90 minutes after the start of fibrinolysis. Patients were referred for rescue PCI within 24 hours. Patients were divided according to time delay from rescue PCI into 3 equal groups: Group A had PCI 3-6 hours after failed thrombolysis, group B had PCI 6-12 hours after failed thrombolysis and group C had PCI 12-24 hours after failed thrombolysis. Patients were studied for the incidence of major adverse cardiac events (MACE), i.e. death; reinfarction, target vessel revascularization (TVR), rehospitalization, symptomatic heart failure and LVEF in the acute stage and after 3 months follow up as primary end points. Left ventricular performance and viability were followed up using low dose dobutamine stress echocardiography as secondary endpoints. Results: Total 63 patients enrolled in the study with mean age 58.60 ± 10.42 years. 84.1% were males and 15.9% were females. Diabetic patients were 65%, hypertensives and smokers were 65% and 42.9% respectively. All patients underwent rescue PCI with bare metal stents (BMS). Three months follow up showed that group A patients had the lowest incidence of MACE (0.0% for Death, reinfarction, TVR, rehospitalization, and highest mean EF 54.14±6.80 (40 - 65) followed by group B (4.7% for death, 9.5% for re-infarction and 47.0% for rehospitalization) with mean EF 41.47±7.60 (30-85) while group C patient had the highest MACE rates and lowest mean LVEF 34.64±5.60 (20 - 40). There was non-significant increase in mortality and TVR rate between the 3 groups. Re-hospitalization showed a statistically significant difference that increased from 0% in group A to 47.0% in group B and 66.6% in group C. Concerning viability assessed by low dose DSE, there were significant difference between groups. In group A, only 4.7% had non-viable infarcted related area, while this percentage increased in group B and C to 38.0% and 100% respectively. Conclusion: Rescue PCI should be done as early as possible for favorable clinical outcome.

The clinical significance of the incorporation of tissue Doppler imaging into low-dose Dobutamine stress echocardiography in patients with aortic stenosis prior to Transcatheter aortic valve implantation

BackgroundLow-dose dobutamine stress echocardiography (DSE) is indicated in patients with low flow (stroke volume index [SVi] < 35 ml/m2) low gradient (mean pressure gradient < 40 mmHg) and left ventricular ejection fraction (LVEF) < 50% aortic stenosis (AS) to assess LV contractile reserve (> 20% increase in SVi) and severity grade of AS. Severe AS is defined by a mean pressure gradient of 40 mmHg occurring at any time during the test when aortic valve area remains < 1.0 cm2.Case presentationThis case report highlights the utility of mitral annular systolic velocity (S′) by tissue Doppler imaging and peak LV outflow tract (LVOT) velocity as markers of LV intrinsic contractile function during DSE in a patient with low flow low gradient AS and reduced EF prior to transcatheter aortic valve implantation (TAVI).ConclusionsMitral annular S′ and peak LVOT velocities are reliable markers of LV intrinsic contractile function and should be incorporated into routine low-dose DSE.

Safety and feasibility of dobutamine stress echocardiography in symptomatic high gradient aortic stenosis patients scheduled for transcatheter aortic valve implantation.

We aimed to study the safety and feasibility of low-dose dobutamine stress echocardiography in a symptomatic high gradient aortic stenosis population scheduled for transfemoral transcatheter aortic valve implantation (TAVI) and to quantify left ventricular (LV) flow reserve. Fifty patients underwent dobutamine stress echocardiography with 5 minutes increments of 5 μg/kg/min up to 20 μg/kg/min until the heart rate increased ≥20 beats/min from baseline or exceeded 100 beats/min. Other criteria for discontinuing the infusion were major adverse events: ventricular arrhythmia, persistent supraventricular arrhythmia, pulmonary edema, chest pain with significant ST-changes, or minor events: ST-changes, drop in systolic blood pressure >30 mmHg, mild chest pain, and/or dyspnea. LV flow reserve was defined as an increase in stroke volume ≥20% during the test. Of 50 patients, 45 completed the test according to protocol. No patient had major adverse event. Five patients experienced minor side effects: mild chest pain/dyspnea in three, self-terminating atrial flutter in one, and decrease in blood pressure in one. Significant LV flow reserve was observed in 20 patients (40%). Low-dose dobutamine stress test appeared safe and feasible patients with high gradient aortic stenosis, and showed LV flow reserve in a minority of them.