Effects of carvedilol therapy on restrictive diastolic filling pattern in chronic heart failure.

BACKGROUND

Carvedilol therapy during congestive heart failure demonstrated a good efficacy in mortality rate reduction and in improvement of left ventricular (LV) systolic performance. However, currently there is not any finding about the drug's effect on diastolic filling. The aim of this study was to evaluate the effects of beta-blocker treatment on LV diastolic function with an eco-pulsed Doppler ultrasound scanning examination at transmitral level in a group of patients who were affected by heart failure with a restrictive filling pattern.

METHODS

We studied 27 patients with idiopathic or ischemic dilated cardiomyopathy with LV severe systolic disfunction (ejection fraction <35%). Fourteen patients were randomized to receive carvedilol treatment (carvedilol group), and 13 patients continued to receive standard therapy with angiotensin-converting enzyme inhibitors, diuretics, and vasodilators (placebo group). All patients underwent an echo-Doppler ultrasound scanning examination at the beginning of the study and after 4 and 12 months of treatment.

RESULTS

In the carvedilol group, we found a progressive improvement of Doppler ultrasound scanning parameters after 4 months, with a significant increase of A wave (P <.005), deceleration time (DT; P <.02) and isovolumetric relaxation time (IVRT; P <.02). These improvements were confirmed after 1 year of follow-up, whereas patients in the placebo group did not shown any significant modifications. After 1 year, the differences in these groups were more significant for A wave (39 +/- 4 cm/sec carvedilol group vs 30 +/- 4 cm/sec placebo group; P <.0001), for E/A ratio (1.8 +/- 0.2 carvedilol group vs 2.6 +/- 0.5 placebo group; P <.0002), for DT 1(40 +/- 16 msec carvedilol group vs 112 +/- 13 msec placebo group; P <.001), and for IVRT (74 +/- 8 msec carvedilol group vs 57 +/- 7 mesc placebo group; P <.0002). These changes seem to happen before systolic and morphological modifications.

CONCLUSION

Our results show that carvedilol therapy is a means of modifying parameters of diastolic filling favorably in patients with heart failure. These effects seem to be independent of those of systolic function. The improvement of systolic performance occurs after 1 year of treatment. The restrictive filling pattern, related to an unfavorable prognosis, changes toward pseudonormal or altered relaxation pattern during carvedilol therapy. Further investigations with a greater sample size will be necessary to confirm our findings.