Persistent diastolic dysfunction late after valve replacement in severe aortic regurgitation.

BACKGROUND: Regression of left ventricular (LV) hypertrophy with normalization of diastolic function has been reported in patients with aortic stenosis late after aortic valve replacement (AVR). The purpose of the present study was to evaluate the effect of AVR on LV function and structure in chronic aortic regurgitation early and late after AVR. METHODS AND RESULTS: Twenty-six patients were included in the present analysis. Eleven patients with severe aortic regurgitation were studied before, early (21 months) and late (89 months) after AVR through the use of LV biplane angiograms, high-fidelity pressure measurements, and LV endomyocardial biopsies. Fifteen healthy subjects were used as controls. LV systolic function was determined from biplane ejection fraction and midwall fractional shortening. LV diastolic function was calculated from the time constant of LV relaxation, peak filling rates, and myocardial stiffness constant. LV structure was assessed from muscle fiber diameter, interstitial fibrosis, and fibrous content. LV muscle mass decreased significantly by 38% early and 55% late after surgery. Ejection fraction was significantly reduced preoperatively and did not change after AVR (P=NS). LV relaxation was significantly prolonged before surgery (89+/-28 ms) but was normalized late after AVR (42+/-14 ms). Early and late peak filling rates were increased preoperatively but normalized postoperatively. Diastolic stiffness constant was increased before surgery (22+/-6 versus 9+/-3 in control subjects; P=0.0003) and remained elevated early and late after AVR (23+/-4; P=0.002). Muscle fiber diameter decreased significantly after AVR but remained increased at late follow-up. Interstitial fibrosis was increased preoperatively and increased even further early but decreased late after AVR. Fibrosis was positively linearly correlated to myocardial stiffness and inversely correlated to LV ejection fraction. CONCLUSIONS: Patients with aortic regurgitation show normalization of macroscopic LV hypertrophy late after AVR, although fiber hypertrophy persists. These changes in LV myocardial structure late after AVR are accompanied by a change in passive elastic properties with persistent diastolic dysfunction.

Effect of intraventricular dyssynchrony on diastolic function and exercise tolerance in patients with heart failure.

AIMS: Intraventricular dyssynchrony may contribute to the severity of heart failure [congestive heart failure (CHF)]. We assessed the correlates of intraventricular dyssynchrony and evaluated dyssynchrony as an independent predictive variable of exercise intolerance in CHF patients. METHODS AND RESULTS: Eighty-one CHF patients (66 +/- 9 years) underwent cardiopulmonary exercise test. Left ventricular (LV) diastolic function was evaluated by transmitral patterns and tissue Doppler. Intraventricular dyssynchrony was calculated according to time intervals between the onset of QRS and the onset of systolic velocities of basal septum and lateral wall. We divided the patients based on the mean value (40 ms) of dyssynchrony. Patients with intraventricular dyssynchrony (>40 ms) showed higher New York Heart Association class (2.7 +/- 0.6 vs. 2.2 +/- 0.4, P < 0.001), higher brain natriuretic peptide (BNP) (415 +/- 478 vs. 194 +/- 205, P = 0.014), more frequent restrictive transmitral pattern (33 vs. 7%, P = 0.013), higher E/E(a) (13 +/- 7 vs. 10 +/- 6, P = 0.016), lower mitral annulus peak systolic velocity (4.5 +/- 1.1 vs. 5.5 +/- 1.5 cm/s, P = 0.01), and peak oxygen consumption (13.8 +/- 3.5 vs. 18.1 +/- 3.9, P < 0.001), than patients without dyssynchrony (< or =40 ms). Predictors of exercise tolerance were intraventricular dyssynchrony (P = 0.035), log BNP (P = 0.003), and E/E(a) (P = 0.004). CONCLUSION: Intraventricular dyssynchrony correlates with higher LV filling pressure and lower ejection fraction and it is an independent predictor of poor aerobic capacity; it may be helpful for functional evaluation of CHF patients.

Diastolic function and BNP changes during exercise predict oxygen consumption in chronic heart failure patients.

UNLABELLED: B-type natriuretic peptide (BNP) is a diagnostic and prognostic marker in heart failure (CHF) patients. AIM: To assess the relation between BNP, diastolic function and exercise capacity in CHF patients. METHODS: Fifty CHF patients underwent cardiopulmonary exercise testing. BNP levels were determined at baseline and at peak exercise. Patients were divided in two groups: with lower (<14 ml/kg/min) or higher (>or=14 ml/kg/min) peak oxygen consumption (VO(2)). RESULTS: Seventeen patients with lower peak VO(2) showed larger incidence of restrictive pattern of the transmitral flow (7/17 vs 4/33, p =0.036). E/Ea ratio was inversely related with peak VO(2) (r =-0.419, p =0.004) and directly related with BNP levels at baseline (r =0.449, p =0.001) and at peak exercise (r =0.475, p =0.001). LV ejection fraction was similar in the two groups. Independent predictors of exercise tolerance were E/Ea ratio (p =0.003), lg BNP at baseline (p =0.034) and increase in lg BNP during exercise (p =0.038). CONCLUSIONS: In CHF patients, E/Ea ratio is a predictor of exercise tolerance and is related with BNP level at rest and at peak exercise.

Tissue Doppler systolic velocity change during dobutamine stress echocardiography predicts contractile reserve and exercise tolerance in patients with heart failure.

AIMS: Dobutamine stress echocardiography (DSE) is widely used to evaluate myocardial contractile reserve in patients with heart failure (HF). The aim of the study was to assess the relationship between the tissue Doppler (TD) mitral annulus systolic velocity (Sm) change during DSE, contractile reserve, and aerobic exercise capacity in HF patients. METHODS AND RESULTS: Sixty-four HF patients (age 67 ± 9 years, 58% with an ischaemic aetiology, and a mean value of the ejection fraction 29 ± 7%) underwent high-dose DSE. The mean value of the TD mitral annulus septal-lateral Sm change was analysed at rest and at peak DSE. All patients underwent also the cardiopulmonary exercise test. With a receiver operating characteristic analysis, a value of 2.02 cm/s obtained as a stress-rest difference in a mean value of the peak systolic velocity of the mitral annulus (Sm) was the best value for diagnosing the myocardial contractile reserve [area under the curve 0.69 (95% CI 0.56-0.80), sensitivity 69% (95% CI 54-81), specificity 80% (95% CI 45-97)]. The patient population was divided into two groups: with rest-stress Sm change during DSE ≤ 2.02 cm/s and with rest-stress Sm change >2.02 cm/s. Patients with Sm rest-stress >2.02 change during DSE, compared with patients with rest-stress change ≤2.02, showed a lower incidence of severe diastolic dysfunction at rest (16 vs. 46%, P= 0.039) and lower E/Ea values (11 ± 5 vs. 15 ± 6, P = 0.005), similar ejection fraction at rest but higher ejection fraction at peak DSE (53 ± 14 vs. 41 ± 12%, P = 0.001), better myocardial contractile reserve assessed by a pressure-volume relationship (1.89 ± 2.01 vs. 0.58 ± 1.38 mmHg/mL/m(2), P = 0.004), with a lower end-systolic volume (-46 ± 20 vs. -24 ± 19%, P< 0.001), a higher increase in the ejection fraction (23 ± 10 vs. 12 ± 10%, P = 0.001) during DSE, and better peak oxygen consumption (16 ± 4 vs. 13 ± 2 mL/kg/min, P = 0.01). CONCLUSION: In patients with HF, the rest-stress variation of mitral annulus systolic velocities during DSE predicts the presence of myocardial contractile reserve and exercise tolerance.

Pressure-volume relationship during dobutamine stress echocardiography predicts exercise tolerance in patients with congestive heart failure.

BACKGROUND: The pressure-volume relationship (PVR) is a useful method for evaluating left ventricular (LV) myocardial contractility during dobutamine stress echocardiography (DSE). The investigators assessed PVRs, systolic and diastolic function, B-type natriuretic peptide (BNP) levels, and aerobic exercise capacity in patients with congestive heart failure (CHF). METHODS: A total of 84 patients with CHF (mean age, 68 +/- 9 years) underwent high-dose DSE. PVR was defined as the systolic cuff pressure/end-systolic volume index difference between rest and peak DSE. Of these, 67 patients also underwent cardiopulmonary exercise testing. The patients were divided into 3 equal groups on the basis of PVR: lower, intermediate, and higher. RESULTS: PVRs were significantly lower in more symptomatic patients (New York Heart Association class II vs III) (2.17 +/- 1.99 vs 0.91 +/- 0.72 mm Hg/mL/m(2), P < .001). Patients with elevated LV filling pressures (E/Ea >or= 14) showed significantly lower PVRs compared with patients with normal or slightly abnormal LV filling pressures (1.1 +/- 1.1 vs 2.96 +/- 3.11 mm Hg/mL/m(2), P = .006). Patients with higher PVRs showed lower logarithmically transformed BNP levels (2.0 +/- 0.5, 2.5 +/- 0.3, and 2.6 +/- 0.5 pg/mL; P < .001), higher peak oxygen consumption (17 +/- 4, 13 +/- 3, and 12 +/- 3 mL/kg/min; P < .001), and higher rest-stress percentage changes in ejection fraction (80 +/- 50%, 56 +/- 29%, and 22 +/- 32%; P < .001) compared with patients with intermediate and lower PVRs, respectively. The parameters predictive of exercise tolerance were PVR (odds ratio [OR]; 1.582, 95% confidence interval [CI], 1.136-2.204; P = .007), ejection fraction (OR, 1.172; 95% CI, 1.070-1.283; P = .001), log BNP (OR, 0.080; 95% CI, 0.020-0.325; P < .001), and E/Ea (OR, 0.836; 95% CI, 0.733-0.953; P = .007). CONCLUSIONS: In patients with CHF, impaired noninvasively assessed myocardial contractility is related to impaired systolic and diastolic function, higher BNP levels, and poorer exercise tolerance.