Sex differences in heart failure patients assessed by combined echocardiographic and cardiopulmonary exercise testing.

Background: We aimed to test the differences in peak VO2 between males and females in patients diagnosed with heart failure (HF), using combined stress echocardiography (SE) and cardiopulmonary exercise testing (CPET). Methods: Patients who underwent CPET and SE for evaluation of dyspnea or exertional intolerance at our institution, between January 2013 and December 2017, were included and retrospectively assessed. Patients were divided into three groups: HF with preserved ejection fraction (HFpEF), HF with mildly reduced or reduced ejection fraction (HFmrEF/HFrEF), and patients without HF (control). These groups were further stratified by sex. Results: One hundred seventy-eight patients underwent CPET-SE testing, of which 40% were females. Females diagnosed with HFpEF showed attenuated increases in end diastolic volume index (P = 0.040 for sex × time interaction), significantly elevated E/e' (P < 0.001), significantly decreased left ventricle (LV) end diastolic volume:E/e ratio (P = 0.040 for sex × time interaction), and lesser increases in A-VO2 difference (P = 0.003 for sex × time interaction), comparing to males with HFpEF. Females diagnosed with HFmrEF/HFrEF showed diminished increases in end diastolic volume index (P = 0.050 for sex × time interaction), mostly after anaerobic threshold was met, comparing to males with HFmrEF/HFrEF. This resulted in reduced increases in peak stroke volume index (P = 0.010 for sex × time interaction) and cardiac output (P = 0.050 for sex × time interaction). Conclusions: Combined CPET-SE testing allows for individualized non-invasive evaluation of exercise physiology stratified by sex. Female patients with HF have lower exercise capacity compared to men with HF. For females diagnosed with HFpEF, this was due to poorer LV compliance and attenuated peripheral oxygen extraction, while for females diagnosed with HFmrEF/HFrEF, this was due to attenuated increase in peak stroke volume and cardiac output. As past studies have shown differences in clinical outcomes between females and males, this study provides an essential understanding of the differences in exercise physiology in HF patients, which may improve patient selection for targeted therapeutics.

Mechanisms of Effort Intolerance in Patients With Heart Failure and Borderline Ejection Fraction.

Combining echocardiography and cardiopulmonary stress testing allows noninvasive assessment of hemodynamics, and oxygen extraction (A-VO2 difference). We evaluated mechanisms of effort intolerance in patients with heart failure with borderline (40% to 49%) left ventricular ejection fraction (EF) (HF and Borderline Ejection fraction). We included 89 consecutive patients with HF and Borderline Ejection fraction (n = 25; 63.6 ± 14 years, 64% men), control subjects (n = 22), patients with HF with preserved EF (n = 26; EF ≥50%), and patients with HF with reduced EF (n = 16; <40%). Various echo parameters (left ventricular volumes, EF, stroke volume, mitral regurgitation [MR] volume, e', right ventricle end-diastolic area, and right ventricle end-systolic area), and ventilatory or combined parameters (peak oxygen consumption [VO2] and A-VO2 difference) were measured at 4 predefined activity stages. Effort-induced functional MR was frequent and more prevalent in HF and Borderline Ejection fraction than in all the other types of HF. In multivariable analysis heart rate response (p <0.0001), A-VO2 difference (p = 0.02), stroke volume (p = 0.002), and right ventricle end-systolic area were the only independent predictors of exercise capacity in HF and Borderline Ejection fraction but peak EF was not. In HF and Borderline Ejection fraction exercise intolerance is predominantly due to chronotropic incompetence, peripheral factors, and limited stroke volume reserve, which are related to right ventricle dysfunction and functional MR but not to left ventricular ejection fraction. Combined testing can be helpful in determining mechanisms of exercise intolerance in HF and Borderline Ejection fraction.

Discriminating Circulatory Problems From Deconditioning: Echocardiographic and Cardiopulmonary Exercise Test Analysis.

BACKGROUND: Discriminating circulatory problems with reduced stroke volume (SV) from deconditioning, in which the muscles cannot consume oxygen normally, by gas exchange parameters is difficult. METHODS: We performed combined stress echocardiography (SE) and cardiopulmonary exercise tests (CPET) in 110 patients (20 with normal effort capacity, 54 with attenuated SV response, and 36 with deconditioning) to evaluate multiple hemodynamic parameters and oxygen content difference (A-V.o2 Diff) in four predefined activity levels to assess which of the gas measures may help in the discrimination. RESULTS: Reduced anaerobic threshold (AT), low unchanging peak oxygen pulse, periodic breathing, shallow Δ peak oxygen consumption (V.o2)/Δwork rate (WR) ratio, and high expired volume per unit time/carbon dioxide production (V.e/V.co2) slope were all associated with abnormal SV response (P < .05 for all). The best discriminator was V.e/V.co2 slope to V.o2 ratio (≥ 2.7; area under the curve [AUC], 0.79; P < .0001). The optimal gas exchange model included ΔV.o2/ΔWR < 8.6; V.e/V.co2 slope to peak V.o2 ratio ≥ 2.7, and periodic breathing (AUC of 0.84; P < .0001). CONCLUSIONS: The best single gas exchange parameter to discriminate between circulatory problems and deconditioning is V.e/V.co2 slope to peak V.O2 ratio. Combining it with ΔV.o2/ΔWR and periodic breathing improves the discriminative ability.

Impact of Right Ventricular Dysfunction and Tricuspid Regurgitation on Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Right ventricular (RV) dysfunction and tricuspid regurgitation (TR) may coexist with aortic stenosis. The aim of this study was to assess the association between RV dysfunction, TR, associated comorbidities, and outcomes following transcatheter aortic valve replacement (TAVR). METHODS: A retrospective analysis was conducted of baseline and 6-month clinical and echocardiographic parameters, including TR grade, RV size (grade, end-diastolic and end-systolic areas, annular diameter), and function (grade, tricuspid annular plane systolic excursion [TAPSE], fractional area change, Tei index), in 519 consecutive TAVR patients. RESULTS: The prevalence of moderate or greater TR was 11% (n = 59). Although TR was associated with increased mortality (P = .02) in unadjusted analysis, it did not demonstrate an independent association with outcome when adjusted for RV dysfunction (TAPSE; P = .30) or multiple clinical parameters (P ≥ .20). RV parameters associated with poor outcomes included TAPSE (P = .006) and Tei index (P = .005). TAPSE was associated with lower survival even when adjusted for TR (P = .009) and all clinical parameters (P = .01). Persistence of moderate or greater TR 6 months after TAVR seemed to be associated with lower survival (P = .02), even when adjusted for clinical and RV parameters (P = .07). CONCLUSIONS: TR in association with aortic stenosis is frequently progressive despite TAVR but is not independently associated with outcomes. RV function is a stronger driver of adverse outcomes compared with TR itself, and RV quantitative rather than qualitative evaluation is the key to stratify these patients.

Impact of left ventricular filling parameters on outcome of patients undergoing trans-catheter aortic valve replacement.

AIM: To assess the impact of left ventricular (LV) filling parameters on outcomes following trans-catheter aortic valve replacement (TAVR). METHODS AND RESULTS: A total of 526 TAVR patients were compared with 300 patients with severe aortic stenosis (AS) treated conservatively. Clinical variables were collected along with echocardiographic data at baseline, 1 month, and 6 months after study entry. End points included all-cause mortality and the combination of death and heart failure admission. LV filling parameters associated with mortality included reduced A wave velocity (P = 0.005) and shorter deceleration time (DT) (P = 0.0005). DT was superior to all other parameters (P = 0.05) apart from patients with atrial fibrillation in whom E/e' was better. Short DT (<160 ms) was associated with lower survival than long DT (≥220 ms; P = 0.002) or intermediate DT (P = 0.05), even after adjustment for age, gender, stroke volume index (SVI), and co-morbidities. However, patients with short baseline DT exhibited greater improvement in DT, E/A, and systolic pulmonary pressure at follow-up than patients with baseline DT ≥160 ms (P < 0.05 for all time x group interactions). Most importantly, among patients with short DT, TAVR was associated with better survival than conservative treatment (46 ± 7 vs. 28 ± 12% at 3 years, P = 0.05), even after adjustment for age, gender, and SVI (P = 0.05). CONCLUSION: Short DT is an independent predictor of adverse outcome following TAVR. Nevertheless, LV filling parameters improve in most patients post TAVR, and TAVR is associated with improved survival compared with conservative therapy, even in patients with evidence of elevated LV filling. Thus, evidence of elevated LV filling should not be viewed as a contraindication for TAVR.

Mechanisms of Effort Intolerance in Patients With Rheumatic Mitral Stenosis: Combined Echocardiography and Cardiopulmonary Stress Protocol.

OBJECTIVES: This study sought to evaluate mechanisms of effort intolerance in patients with rheumatic mitral stenosis (MS). BACKGROUND: Combined stress echocardiography and cardiopulmonary testing allows assessment of cardiac function, hemodynamics, and oxygen extraction (A-Vo2 difference). METHODS: Using semirecumbent bicycle exercise, 20 patients with rheumatic MS (valve area 1.36 ± 0.4 cm2) were compared to 20 control subjects at 4 pre-defined activity stages (rest, unloaded, anaerobic threshold, and peak). Various echocardiographic parameters (left ventricular volumes, ejection fraction, stroke volume, mitral valve gradient, mitral valve area, tissue s' and e') and ventilatory parameters (peak oxygen consumption [Vo2] and A-Vo2 difference) were measured during 8 to 12 min of graded exercise. RESULTS: Comparing patients with MS to control subjects, significant differences (both between groups and for group by time interaction) were seen in multiple parameters (heart rate, stroke volume, end-diastolic volume, ejection fraction, s', e', Vo2, and tidal volume). Exercise responses were all attenuated compared to control subjects. Comparing patients with MS and poor exercise tolerance (<80% of expected) to other subjects with MS, we found attenuated increases in tidal volume (p = 0.0003), heart rate (p = 0.0009), and mitral area (p = 0.04) in the poor exercise tolerance group. These patients also displayed different end-diastolic volume behavior over time (group by time interaction p = 0.05). In multivariable analysis, peak heart rate response (p = 0.01), tidal volume response (p = 0.0001), and peak A-Vo2 difference (p = 0.03) were the only independent predictors of exercise capacity in patients with MS; systolic pulmonary pressure, mitral valve gradient, and mitral valve area were not. CONCLUSIONS: In patients with rheumatic MS, exercise intolerance is predominantly the result of restrictive lung function, chronotropic incompetence, limited stroke volume reserve, and peripheral factors, and not simply impaired valvular function. Combined stress echocardiography and cardiopulmonary testing can be helpful in determining mechanisms of exercise intolerance in patients with MS.

Determinants of Effort Intolerance in Patients With Heart Failure: Combined Echocardiography and Cardiopulmonary Stress Protocol.

OBJECTIVES: The purpose of this study was to assess individual mechanisms of effort intolerance in patients with heart failure with preserved ejection fraction (HFpEF), heart failure with reduced ejection fraction (HFrEF), or normal cardiac function using combined echocardiography and cardiopulmonary stress testing. BACKGROUND: Combined stress echocardiography and cardiopulmonary tests visualize cardiac chambers in 4 well-defined activity levels (rest, unloaded, anaerobic threshold, and peak), allowing noninvasive assessment of cardiac function, hemodynamics, and arterial venous oxygen content difference (AVo(2)Diff) during all stages. METHODS: Left ventricular volumes, stroke volume (SV), S', E/e', oxygen consumption (Vo(2)), and AVo(2)Diff were measured in all effort stages using ramp semirecumbent cycle prolonged (≥8 min) exercise in 45 consecutive subjects evaluated for effort intolerance (14 normal cardiac function, 16 HFpEF, and 15 HFrEF patients; age 56.5 ± 16 years; 73% male). RESULTS: In HFpEF and HFrEF, the changes in Vo2 were attenuated (between group p = 0.003; group by time interaction p < 0.0001), as well as peak heart rate (p = 0.0001; p = 0.0001) and SV (p = 0.006; p = 0.0001). End-diastolic volume to E/e' ratio (measure of compliance) was superior in HFrEF and normal patients at baseline but worsened in HFpEF and HFrEF at peak exercise (8.3 ± 4 vs. 11.6 ± 5 vs. 19.1 ± 8; p = 0.004; p = 0.01). Functional mitral regurgitation worsened even during the unloaded stage, mostly in patients with HFrEF, but also in several patients with HFpEF. In multivariable analysis, heart rate response (p = 0.007), and AVo(2)Diff (p < 0.0001) were the most significant independent predictors of effort capacity; SV was not. CONCLUSIONS: Combined tests are feasible and allow noninvasive evaluation of effort intolerance. In HFpEF and HFrEF patients, exercise intolerance is predominantly due to chronotropic incompetence and peripheral factors. Combined stress echocardiography and cardiopulmonary tests may have potential for clinical management and selection of patients for trials.

Hemodynamic impact and outcome of permanent pacemaker implantation following transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) frequently requires postprocedural permanent pacemaker (PPM) implantation. We evaluated clinical and hemodynamic impact of PPM after TAVI. Clinical and echocardiographic data were retrospectively analyzed in 230 consecutive patients who underwent TAVI and echocardiography at baseline and after 6 months. Echocardiographic parameters included left ventricular ejection fraction (LVEF), left ventricular (LV) stroke volume, early mitral velocity/annulus velocity ratio (E/e'), right ventricular index of myocardial performance, systolic pulmonary artery pressure (SPAP), and aortic, mitral, and tricuspid regurgitation grades. Clinical outcomes included 2-year survival and cardiovascular and PPM-related event-free survival. The Medtronic CoreValve and Edwards Sapien prosthesis were used in 201 and 29 patients, respectively. PPM was required in 58 patients (25.4%). Two-year and event-free survival rates were similar between patients with and without PPM. At 6 months, patients with PPM demonstrated attenuated improvement in LVEF (-0.9 ± 8.7% vs 2.3 ± 10.8%, respectively, p = 0.03) and LV stroke volume (-2 ± 16 vs 4 ± 10 ml/m(2), respectively, p = 0.015), a trend toward smaller reduction in systolic pulmonary artery pressure (-1 ± 12 vs -6 ± 10 mm Hg, respectively, p = 0.09), and deterioration of right ventricular index of myocardial performance (-3 ± 17% vs 5 ± 26%, respectively, p = 0.05). The differences in post-TAVI aortic, mitral, and tricuspid regurgitation grades were insignificant. In conclusion, PPM implantation after TAVI is associated with reduced LVEF and impaired LV unloading. However, this unfavorable hemodynamic response does not affect the 2-year clinical outcome. The maintenance of clinical benefit appears to be driven by TAVI-related recovery of LV and right ventricular performance that mitigates unfavorable impact of PPM.