Higher Stroke Volume Index Research Articles

Optimal stroke volume index cut off for survival of severe aortic stenosis patients undergoing TAVI - where should we draw the line?

Abstract Funding Acknowledgements Type of funding sources: None. Background Low-flow status in patients with severe aortic stenosis (SAS) is currently defined using stroke volume index (SVi), at a cut off below 35mL/m2. Low-flow has been associated with higher mortality in patients undergoing transcatheter aortic valve implantation (TAVI). However, different cut offs have been recently suggested to more accurately define a low-SVi associated with worse survival after valvular intervention. Purpose Determine the impact of SVi in mortality of SAS patients undergoing TAVI and define a prognostically relevant threshold in this context. Methods A database comprising all patients treated with TAVI between 2011 and 2019 in a single-centre was retrospectively analyzed, and cases with echocardiograms performed before intervention in our centre were included. Primary endpoint was defined as time to all-cause death or last follow-up over the five years after intervention. Surv_cutpoint from survival package in R was used to evaluate optimal low-SVi cutpoints associated with worse survival in SAS patients undergoing TAVI. Low-flow patients were compared with normal-flow counterparts using the determined low-SVi definition. The prognostic values of continuous and categorical SVi at a <35mL/m2 cut off and using the newly determined threshold were tested using Kaplan-Meier curves, log-rank test and Cox proportional hazard model adjusted for EuroSCORE II. Patients were further divided as having preserved or reduced ejection fraction (EF, <52%). p<0.05 was considered statistically significant. Results Of 657 TAVI performed, 488 (74.6%) patients were included in the present analysis, over a median follow-up of 56 months. A SVi<35ml/m2 was not associated with higher mortality after TAVI (p = 0.07). An optimal cutpoint of low-SVi was defined at <29mL/m2 (n=115, 24%), and these patients were on a more advanced NYHA class, were of higher estimated surgical risk, were more frequently hypertensive and anemic, and had a higher prevalence of atrial fibrillation. Echocardiographic data revealed lower EF, lower functional aortic valve area and lower transvalvular gradients in low-SVi patients. Regarding TAVI design, a balloon-expandable valve was more frequently used in this setting. SVi<29ml/m2 was associated with higher mortality after intervention [p = 0.003, hazard ratio (HR) 1.60 (1.18–2.17)], including after adjusting to EuroSCORE II, and in a reduced (but not preserved) EF context. When analyzed as a continuous variable, a higher SVi was associated with better survival after TAVI. Conclusions SVi is a prognostically relevant parameter in SAS patients undergoing TAVI. Contrary to a classically defined threshold of <35mL/m2, a SVi<29mL/m2 was associated with higher mortality after intervention in our population.

Cardiologic Manifestations in Omicron‐Type Versus Wild‐Type COVID‐19: A Systematic Echocardiographic Study

Background Information about the cardiac manifestations of the Omicron variant of COVID-19 is limited. We performed a systematic prospective echocardiographic evaluation of consecutive patients hospitalized with the Omicron variant of COVID-19 infection and compared them with similarly recruited patients were propensity matched with the wild-type variant. Methods and Results A total of 162 consecutive patients hospitalized with Omicron COVID-19 underwent complete echocardiographic evaluation within 24 hours of admission and were compared with propensity-matched patients with the wild-type variant (148 pairs). Echocardiography included left ventricular (LV) systolic and diastolic, right ventricular (RV), strain, and hemodynamic assessment. Echocardiographic parameters during acute infection were compared with historic exams in 62 patients with the Omicron variant and 19 patients with the wild-type variant who had a previous exam within 1 year. Of the patients, 85 (53%) had a normal echocardiogram. The most common cardiac pathology was RV dilatation and dysfunction (33%), followed by elevated LV filling pressure (E/e' ≥14, 29%) and LV systolic dysfunction (ejection fraction <50%, 10%). Compared with the matched wild-type cohort, patients with Omicron had smaller RV end-systolic areas (9.3±4 versus 12.3±4 cm2; P=0.0003), improved RV function (RV fractional-area change, 53.2%±10% versus 39.7%±13% [P<0.0001]; RV S', 12.0±3 versus 10.7±3 cm/s [P=0.001]), and higher stroke volume index (35.6 versus 32.5 mL/m2; P=0.004), all possibly related to lower mean pulmonary pressure (34.6±12 versus 41.1±14 mm Hg; P=0.0001) and the pulmonary vascular resistance index (P=0.0003). LV systolic or diastolic parameters were mostly similar to the wild-type variant-matched cohort apart from larger LV size. However, in patients who had a previous echocardiographic exam, these LV abnormalities were recorded before acute Omicron infection, but not in the wild-type cohort. Numerous echocardiographic parameters were associated with higher in-hospital mortality (LV ejection fraction, stroke volume index, E/e', RV S'). Conclusions In patients with Omicron, RV function is impaired to a lower extent compared with the wild-type variant, possibly related to the attenuated pulmonary parenchymal and/or vascular disease. LV systolic and diastolic abnormalities are as common as in the wild-type variant but were usually recorded before acute infection and probably reflect background cardiac morbidity. Numerous LV and RV abnormalities are associated with adverse outcome in patients with Omicron.

Flow-status and survival in severe aortic stenosis treated with TAVI – is flow rate superior to stroke volume index?

Abstract Background Low-flow status, currently defined as a stroke volume index (SVi) &amp;lt;35 mL/m2, is an important prognostic predictor for mortality after Transcatheter Aortic Valve Implantation (TAVI) for severe aortic stenosis (SAS). However, transaortic flow rate (FR) – defined as stroke volume divided by left ventricle ejection time - has recently been suggested to be superior to SVi in defining low-flow states, as it reflects more closely valvular resistance, while being independent of body surface area. Low FR is most consistently defined as FR&amp;lt;200 mL/s. Purpose Determine the prognostic impact of FR and SVi before TAVI in survival after intervention for SAS. Methods A single-centre retrospective database of all TAVI performed between 2011 and 2019 was analyzed, and cases with pre-intervention echocardiograms available were included. Low-flow patients were identified according to basal FR (&amp;lt;200 mL/s) or SVi (&amp;lt;35 mL/m2), and compared with normal-flow cases. The primary endpoint was defined as time to all-cause death or last follow-up. The impact of flow-status (using FR or SVi) in survival was assessed using Kaplan-Meier curves and log-rank test, as well as Cox proportional hazard model adjusted for EuroSCORE II, using FR or SVi either as categorical or continuous variables. A subanalysis further compared patients with preserved and reduced ejection fraction (EF, &amp;lt;52%). p&amp;lt;0.05 was considered statistically significant. Results From 657 TAVI performed, 490 (74.6%) cases were included, with a median follow-up of 43 months. From those, 59.6% were defined as low-flow according to FR, and 43.3% using SVi. Low-flow patients, using each parameter, were of higher surgical risk (EuroSCORE II and STS scores), had more advanced NYHA classes, worse estimated creatinine clearance, and suffered more frequently from coronary artery disease. Low-FR patients were also older, and more predominantly female. Atrial fibrillation was more prevalent among low SVi cases. Functional aortic valve area was lower in low-flow patients using both assessments, but low-SVi was also associated with lower transaortic gradients, as well as lower EF before and after TAVI. Regarding all-cause mortality, low-SVi was associated with worse survival [p=0.02, hazard ratio (HR) 1.43 (1.05–1.94)], but not low-FR (p=0.4). However, low-SVi, when adjusted for EuroScore II, was no longer a predictor of all-cause mortality (p=0.08). When considering FR and SVi as continuous variables, a higher SVi (but not FR) was associated with better survival (HR 0.98, p=0.047) in multivariable analysis adjusted for EuroSCORE II. When stratifying according to preserved and reduced EF, both FR and SVi did not predict all-cause mortality. Conclusions Low-flow states are common in SAS population treated with TAVI, being frequently associated with worse symptoms and higher procedural risk. Low-SVi, but not low-FR, negatively impacts survival after intervention, representing a marker for prognosis after TAVI. Funding Acknowledgement Type of funding sources: None.

Renal Sympathetic Denervation in Patients With Heart Failure With Preserved Ejection Fraction.

Arterial hypertension is the most common comorbidity in patients with heart failure with preserved ejection fraction (HFpEF) and mediates adverse hemodynamics through related aortic stiffness and increased pulsatile load. We aimed to investigate the clinical and hemodynamic implications of renal sympathetic denervation (RDN) in patients with HFpEF and uncontrolled arterial hypertension. Patients undergoing RDN between 2011 and 2018 in a single-center were retrospectively analyzed and classified as HFpEF (n=99) or no HF (n=65). Stroke volume index and aortic distensibility were measured through cardiac magnetic resonance imaging, and left ventricular (LV) systolic and diastolic properties were assessed echocardiographically. At baseline, patients with HFpEF had higher stroke volume index (median 40 [interquartile range, 33-48] versus 33 [26-40] mL/m2, P=0.002), pulse pressure (69 [63-77] versus 61 [55-67] mm Hg, P<0.001), but lower LV-VPES100mm Hg (18 [10-28] versus 24 [15-40] mL, P=0.007) and aortic distensibility (1.5 [1.1-2.6] versus 2.7 [1.1-3.5] 10-3 mm Hg-1, P=0.013) as compared to no-HF patients. Systolic blood pressure decreased comparable in patients with HFpEF and no-HF patients following RDN (-9 [-16 to -2], P<0.001). After RDN stroke volume index (-3 [-9 to +3] mL/m2, P=0.011) decreased and aortic distensibility (0.2 [-0.1 to +1.1] 10-3 mm Hg-1, P=0.007) and systolic stiffness (P<0.001) increased in HFpEF patients. LV diastolic stiffness and LV filling pressures as well as NT-proBNP (N-terminal pro-B-type natriuretic peptide) decreased after RDN in patients with HFpEF (P=0.032, P=0.043, and P<0.001, respectively). Patients with HFpEF undergoing RDN showed increased stroke volume index, vascular, and LV stiffness as compared to no-HF patients. Following RDN those hemodynamic alterations and reduced systolic and diastolic LV stiffness were partly normalized, implying RDN might be a potential therapeutic strategy for arterial hypertension and HFpEF.

Mild Aortic Valve Stenosis Predicts Worse Survival after Hospital Admission for Heart Failure with Preserved Ejection Fraction

Introduction Mild aortic stenosis (AS) and aortic sclerosis are associated with increased mortality in the general population, which may be mediated by their reflection of underlying inflammation and obesity, both risk factors for HFpEF. Hypothesis Patients with HFpEF and mild AS or aortic sclerosis constitute a distinct phenotype with worse prognosis. Methods Consecutive HFpEF patients, admitted to Mayo Clinic Rochester between 2010-2015 for treatment with intravenous diuretics, were included. Patients with more than mild AS or more than mild mitral stenosis were excluded. Mild AS was defined as an aortic peak jet velocity 1.9-2.9 m/s. Extensive valvular leaflet thickening/calcification with normal peak jet velocity (≤1.8 m/s) was classified as aortic sclerosis. All-cause mortality and death causes were registered with censoring at last contact. Results In 370 HFpEF patients (age 77±13 years; 58% women), 111 had mild AS (30%), while 104 had aortic sclerosis (28%). Patients with mild AS or aortic sclerosis were significantly older with worse renal function and a lower lean body mass. Patients with mild AS (but not aortic sclerosis) had a higher stroke volume index [41 mL/m² (34-48 mL/m²) versus 46 mL/m² (40-52 mL/m²) in controls with a normal aortic valve; age-adjusted P-value<0.001] and an increased preload-recruitable stroke work (98.1±27.3 erg.cm−³.10³ versus 91.4±26.2 erg.cm−³.10³ in controls; age-adjusted P-value = 0.021). E/e’ decreased from mild AS [20.0 (15.0-25.0)], over aortic sclerosis [17.1 (12.9-23.7)] to controls [15.7 (12.0-20.0); age-adjusted P-value<0.001 for trend]. Over 38±32 months of follow-up, 247 patients died (67%) with mortality causes retrieved in 205 cases (83%). Both mild AS [HR (95%CI) = 1.57 (1.17-2.12)] and aortic sclerosis [HR (95%CI) = 1.51 (1.11-2.05)] were associated with all-cause mortality (Figure). After adjusting for differences in baseline characteristics, the hazard of aortic sclerosis disappeared, while the hazard of increased peak jet velocity remained statistically significant [HR (95%CI) = 1.31 (1.01-1.70) per 1 m/s; P-value = 0.042]. Patients with mild AS versus a normal aortic valve had less non-HF cardiovascular mortality (2.9% versus 18.4%) and more deaths due to comorbid conditions (44.1% versus 28.9%). Conclusions Mild AS in HFpEF is associated with increased mortality and a shift from non-HF cardiovascular towards comorbidity-driven deaths. While the risk of valvular sclerosis/calcification is mediated by age and comorbidities, an elevated peak jet velocity may indicate a distinct phenotype with increased stroke volume and contractility but poor outcome. Mild aortic stenosis (AS) and aortic sclerosis are associated with increased mortality in the general population, which may be mediated by their reflection of underlying inflammation and obesity, both risk factors for HFpEF. Patients with HFpEF and mild AS or aortic sclerosis constitute a distinct phenotype with worse prognosis. Consecutive HFpEF patients, admitted to Mayo Clinic Rochester between 2010-2015 for treatment with intravenous diuretics, were included. Patients with more than mild AS or more than mild mitral stenosis were excluded. Mild AS was defined as an aortic peak jet velocity 1.9-2.9 m/s. Extensive valvular leaflet thickening/calcification with normal peak jet velocity (≤1.8 m/s) was classified as aortic sclerosis. All-cause mortality and death causes were registered with censoring at last contact. In 370 HFpEF patients (age 77±13 years; 58% women), 111 had mild AS (30%), while 104 had aortic sclerosis (28%). Patients with mild AS or aortic sclerosis were significantly older with worse renal function and a lower lean body mass. Patients with mild AS (but not aortic sclerosis) had a higher stroke volume index [41 mL/m² (34-48 mL/m²) versus 46 mL/m² (40-52 mL/m²) in controls with a normal aortic valve; age-adjusted P-value<0.001] and an increased preload-recruitable stroke work (98.1±27.3 erg.cm−³.10³ versus 91.4±26.2 erg.cm−³.10³ in controls; age-adjusted P-value = 0.021). E/e’ decreased from mild AS [20.0 (15.0-25.0)], over aortic sclerosis [17.1 (12.9-23.7)] to controls [15.7 (12.0-20.0); age-adjusted P-value<0.001 for trend]. Over 38±32 months of follow-up, 247 patients died (67%) with mortality causes retrieved in 205 cases (83%). Both mild AS [HR (95%CI) = 1.57 (1.17-2.12)] and aortic sclerosis [HR (95%CI) = 1.51 (1.11-2.05)] were associated with all-cause mortality (Figure). After adjusting for differences in baseline characteristics, the hazard of aortic sclerosis disappeared, while the hazard of increased peak jet velocity remained statistically significant [HR (95%CI) = 1.31 (1.01-1.70) per 1 m/s; P-value = 0.042]. Patients with mild AS versus a normal aortic valve had less non-HF cardiovascular mortality (2.9% versus 18.4%) and more deaths due to comorbid conditions (44.1% versus 28.9%). Mild AS in HFpEF is associated with increased mortality and a shift from non-HF cardiovascular towards comorbidity-driven deaths. While the risk of valvular sclerosis/calcification is mediated by age and comorbidities, an elevated peak jet velocity may indicate a distinct phenotype with increased stroke volume and contractility but poor outcome.

Inconsistency in aortic stenosis severity between CT and echocardiography: prevalence and insights into mechanistic differences using computational fluid dynamics

ObjectivesThe aims of this study were to evaluate the inconsistency of aortic stenosis (AS) severity between CT aortic valve area (CT-AVA) and echocardiographic Doppler parameters, and to investigate potential underlying...

Exercise impedance cardiography reveals impaired hemodynamic responses to exercise in hypertensives with dyspnea.

Patients with arterial hypertension (AH), especially women, often report exercise intolerance and dyspnea. However, these symptoms are not frequently reflected in standard assessments. The aim of the study was to evaluate the clinical value of impedance cardiography (ICG) in the hemodynamic assessment of patients with AH during exercise, particularly the differences between subgroups based on sex and the presence of dyspnea. Ninety-eight patients with AH (52 women; 54.5 ± 8.2 years of age) were evaluated for levels of N-terminal pro-B-type brain natriuretic peptide (NT-proBNP), exercise capacity (cardiopulmonary exercise testing (CPET) and the 6-min walk test (6MWT)), and exercise ICG. Patients with AH were stratified into the following four subgroups: males without dyspnea (MnD, n = 38); males with dyspnea (MD, n = 8); females without dyspnea (FnD, n = 27); and females with dyspnea (FD, n = 25). In comparison with the MnD subgroup, the FnD subgroup demonstrated significantly higher NT-proBNP levels; lower exercise capacity (shorter 6MWT distance, lower peak oxygen uptake (VO2), lower O2 pulse); higher peak stroke volume index (SVI); and higher SVI at the anaerobic threshold (AT). In comparison with the other subgroups, the FD subgroup walked a shorter distance during the 6MWT distance; had a steeper VE/VCO2 slope; had lower values of peak stroke volume (SV) and peak cardiac output (CO); and had a smaller change in CO from rest to peak. However, no other differences were identified (NT-proBNP, left ventricular diastolic dysfunction, or CPET parameters). Exercise impedance cardiography revealed an impaired hemodynamic response to exercise in hypertensive females with dyspnea. In patients with unexplained exercise intolerance, impedance cardiography may complement traditional exercise tests.

EXERCISE IMPEDANCE CARDIOGRAPHY REVEALS IMPAIRED HEMODYNAMIC RESPONSE TO EXERCISE IN HYPERTENSIVES WITH DYSPNEA

Objective: Patients with arterial hypertension (AH), especially women, often report exercise intolerance and dyspnea. However, subjective symptoms are frequently not reflected in standard, objective assessments. The aim of the study was to assess multiple parameters during controlled exercise in patients with AH, particularly the differences between subgroups identified based on sex and symptoms of reduced exercise tolerance. Design and method: Ninety-eight patients with AH (52 women; age 54.5 ± 8.2 years) were evaluated for dyspnea, levels of the NT-proBNP, exercise capacity (with cardiopulmonary exercise testing (CPET) and a 6-minute walk test (6MWT)), and hemodynamic parameters (by means of impedance cardiography) during exercise. Patients with AH were stratified by sex and history of dyspnea, yielding four subgroups: males without dyspnea (MnD, n = 38); males with dyspnea (MD, n = 8); females without dyspnea (FnD, n = 27); females with dyspnea (FD, n = 25). Results: In comparison with MnD, the FnD subgroup demonstrated higher NT-proBNP levels (29.5 ± 25.5 vs. 103.1 ± 71.6 pg/mL, p < 0.001); lower exercise capacity: shorter 6MWT distance (595.3 ± 91.5 vs. 522.9 ± 56.6 m, p < 0.001); lower peak oxygen uptake (VO2) (22.7 ± 5.2 vs. 17.0 ± 3.7 mL/min/kg, p < 0.001); higher peak stroke volume index (SVI) (52.4 ± 8.9 vs. 61.7 ± 11.2 mL/m2, p = 0.004); and higher SVI at the anaerobic threshold (AT) (50.1 ± 10.4 vs. 59.5 ± 12.6 mL, p = 0.011). In comparison with FnD, the FD subgroup covered a shorter distance during the 6MWT distance (522.9 ± 56.6 vs. 466.1 ± 87.2 m, p = 0.017), had a steeper VE/VCO2 slope (25.5 ± 2.4 vs. 29.0 ± 5.5, p = 0.004); lower values of peak stroke volume (SV) (117.4 ± 22.4 vs. 99.7 ± 18.1 mL, p = 0.017), peak cardiac output (CO) (17.0 ± 3.7 vs. 13.1 ± 2.9 L/min, p = 0.002) and lower change in CO (peak–rest) (10.5 ± 3.6 vs. 7.2 ± 2.7 L/min, p = 0.004). However, no other differences were identified (NT-proBNP, left ventricular diastolic dysfunction, or CPET parameters) Conclusions: Exercise impedance cardiography revealed an impaired hemodynamic response to exercise in hypertensive females with dyspnea. In patients with unexplained exercise intolerance exercise impedance cardiography may complement traditional exercise tests.

Cardio-haemodynamic assessment and venous lactate in severe dengue: Relationship with recurrent shock and respiratory distress.

BackgroundDengue can cause plasma leakage that may lead to dengue shock syndrome (DSS). In approximately 30% of DSS cases, recurrent episodes of shock occur. These patients have a higher risk of fluid overload, respiratory distress and poor outcomes. We investigated the association of echocardiographically-derived cardiac function and intravascular volume parameters plus lactate levels, with the outcomes of recurrent shock and respiratory distress in severe dengue.Methods/Principle findingsWe performed a prospective observational study in Paediatric and adult ICU, at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam. Patients with dengue were enrolled within 12 hours of admission to paediatric or adult ICU. A haemodynamic assessment and portable echocardiograms were carried out daily for 5 days from enrolment and all interventions recorded.102 patients were enrolled; 22 patients did not develop DSS, 48 had a single episode of shock and 32 had recurrent shock. Patients with recurrent shock had a higher enrolment pulse than those with 1 episode or no shock (median: 114 vs. 100 vs. 100 b/min, P = 0.002), significantly lower Stroke Volume Index (SVI), (median: 21.6 vs. 22.8 vs. 26.8mls/m2, P<0.001) and higher lactate levels (4.2 vs. 2.9 vs. 2.2 mmol/l, P = 0.001). Higher SVI and worse left ventricular function (higher Left Myocardial Performance Index) on study days 3–5 was associated with the secondary endpoint of respiratory distress. There was an association between the total IV fluid administered during the ICU admission and respiratory distress (OR: 1.03, 95% CI 1.01–1.06, P = 0.001). Admission lactate levels predicted patients who subsequently developed recurrent shock (P = 0.004), and correlated positively with the total IV fluid volume received (rho: 0.323, P = 0.001) and also with admission ALT (rho: 0.764, P<0.001) and AST (rho: 0.773, P<0.001).Conclusions/SignificanceEcho-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of recurrent shock and respiratory distress in ICU. These findings may serve to, not only assist in the management of DSS patients, but also these haemodynamic endpoints could be used in future dengue fluid intervention trials.

Influence of sex, menstrual cycle, and oral contraceptives on cerebrovascular resistance and cardiorespiratory function during Valsalva or standing.

Women experience orthostatic intolerance more than men, and they experience faintness more in the early follicular [i.e., low-hormone (LH)] than luteal [i.e., high-hormone (HH)] phase of the menstrual cycle. Men (n = 13, 25.8 ± 1.8 yr old) and women in the LH (days 2-5; placebo) and HH (days 18-24; high dose) phases of the menstrual cycle with (OC; n = 14, 22.0 ± 0.8 yr old) or without (NOC; n = 12, 21.8 ± 0.5 yr old) oral contraceptive (OC) use underwent the Valsalva maneuver and a supine-sit-stand protocol. Blood pressure, normalized stroke volume [stroke volume index (SVi)], cardiac output index, heart rate, end-tidal CO2, and middle cerebral artery (MCA) blood flow velocity were measured. When subjected to the Valsalva maneuver, all women had a greater increase in diastolic and mean MCA blood flow velocity than men (P ≤ 0.065), with no significant effect of menstrual cycle phase or OC use. When subjected to the supine-sit-stand protocol, men had lower MCA blood flow velocity (P < 0.038) than all women, and SVi was higher in men than in the NOC group in all postures (P < 0.011) and in the OC group in the LH phase of the menstrual cycle during standing (P = 0.010). Only men experienced higher resistance index (P < 0.001) and pulsatility index (P < 0.001) with standing. The OC group had lower end-tidal CO2 (P = 0.002) than the NOC group (P = 0.030) and men (P ≤ 0.067). SVi (P = 0.004) and cardiac output index (P = 0.008) were higher in the OC than NOC group. A tendency toward a lower mean MCA blood flow velocity (P = 0.058) and higher SVi (P = 0.059) and pulsatility index (P = 0.058) was noted in the HH than LH phase. Mean arterial pressure was higher in the OC than NOC group in the LH phase (P = 0.049) and lower in the HH than LH phase (P = 0.014). Our results indicate that cycling estrogens/progestins can influence ventilatory, cardiovascular, and/or cerebrovascular physiology.NEW & NOTEWORTHY We have found sex differences in the cerebrovascular response to the Valsalva maneuver and standing. Men have greater cerebral vasoconstriction (or women have greater cerebral vasodilation) during late phase II of the Valsalva maneuver, and the cerebrovascular resistance index increases in men, but not in women, during standing. Furthermore, our findings indicate that both the menstrual cycle phase and oral contraceptive use can influence cardiovascular function both at rest and during active standing.

Target temperature management of 33°C exerts benefi cial haemodynamic eff ects after out-of-hospital cardiac arrest

Background Accumulating evidence indicates that target temperature management (TTM) is benefi cial in patients resuscitated after cardiac arrest since it appears to improve neurological outcome. However, the optimal cooling method (surface vs intravascular) has not yet been specifi ed. Substantial heart disease is present in most of these patients and therefore haemodynamic eff ects of cooling need to be considered very carefully. We analysed the haemodynamic response to TTM in patients treated with surface versus intravascular cooling following out-of-hospital cardiac arrest.Methods and results In this observational study 63 consecutive subjects presenting to the hospital after successful resuscitation following of out-of-hospital cardiac arrest received an intravascular (40 patients) or external cooling device (23 patients) to induce TTM. While with intravascular cooling the target temperature of 33°C was reached after 159 minutes, the minimum temperature achieved with surface cooling was about 35°C after 437 minutes. Haemodynamic parameters were recorded in a 4-hour rhythm for the fi rst 12 hours after induction of hypothermia. Generally, TTM of 33°C resulted in a higher systemic vascular resistance index (749 vs 467 dyn*sec/cm5/m²; P= 0.04) but also in a marked reduction of heart rate (67.70 vs 100.00 bpm; P < 0.001), a higher mixed venous oxygen saturation (76 vs 68%; P= 0.016), and a higher stroke volume index (45 vs 33 ml/m²; P= 0.036). TTM additionally resulted in a higher cardiac power index (0.55 vs 0.46 Watt/m²; P= 0.024).Conclusion TTM of 33°C compared to 35°C exerts benefi cial haemodynamic eff ects and might be viewed as an adjunct inotropic therapy avoiding the undesired side eff ects of vasoactive substances.

Neuropsychological function in patients with end-stage heart failure before and after cardiac transplantation

This study was performed to examine cognitive function in patients with end-stage heart failure, to identify possible cardiovascular factors associated with cognitive function, and to evaluate changes in cognitive function in a subgroup of patients who received heart transplantation. An extensive battery of neuropsychological tests were given to 62 patients with end-stage cardiac failure as part of their evaluation for cardiac transplantation. Most patients were consecutive referrals, not selected because of cognitive complaints. A small subgroup of transplanted (n = 7) and non-transplanted (n = 4) patients received a repeat neuropsychological examination. At initial examination, approximately 50% of the patients met criteria for impairment in reference to normal control values. Higher stroke volume index and cardiac index and lower right atrial pressure were correlated with better cognitive function. In the subgroup of patients re-examined, the transplanted patients demonstrated significantly improved cognitive function, whereas the non-transplanted subjects were unchanged. These data indicate that in patients with end-stage heart failure there is a high prevalence of impaired cognitive function which is related to measures of cardiovascular efficiency. Preliminary evidence suggests that these impairments may be partially ameliorated by cardiac transplantation.