Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study

Abstract

Objective: To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol.

Design: Retrospective analysis of serial echocardiograms in 257 patients with chronic systolic heart failure at baseline and at 12-18 months after starting carvedilol. Reverse left ventricular remodelling was determined by changes in left ventricular end diastolic dimension (LVEDD), end systolic dimension (LVESD), and fractional shortening (LVFS).

Setting: Heart failure clinic within a university teaching hospital.

Main outcome measures: Changes in LVEDD, LVESD, and LVFS.

Results: LVEDD and LVESD decreased by 2.6 (0.4) mm and 4.9 (0.5) mm, respectively (mean (SEM)), and LVFS increased by 4.3 (0.5)% (all p < 0.0001 v baseline). Simple regression revealed no significant relation between BHR or HRR and the changes in LVEDD, LVESD, or LVFS. Stratification of patients into high and low BHR groups (above and below the mean) or according to the baseline heart rhythm (sinus rhythm v atrial fibrillation) showed no differences between groups in the extent of reverse left ventricular remodelling. Improvements in left ventricular function and dimensions were associated with significant improvements in New York Heart Association functional class.

Conclusions: The benefits of carvedilol in terms of reverse left ventricular remodelling and symptomatic improvement in patients with chronic heart failure are independent of BHR, heart rhythm, and the HRR that occurs in response to carvedilol.

Figure 1

Relation between heart rate reduction, baseline heart rate, and heart rhythm. (A) Linear regression plot of heart rate change after 12 months of carvedilol v baseline heart rate (BHR). (B) and (C) Mean heart rate (with standard error bars) measured at baseline (HR B) and after 12 months of carvedilol (HR 12), stratified according to high and low BHR groups (B) and according to baseline rhythm (C). AF, atrial fibrillation; SR, sinus rhythm. ***p < 0.001 v baseline; ****p < 0.0001 v baseline.

Figure 2

Scatterplots showing the relations between changes in LVESD and baseline heart rate (A) and heart rate reduction (B). No significant associations were identified for any of the plotted variables. AF, atrial fibrillation; LVESD, left ventricular end systolic dimension; SR, sinus rhythm.

Figure 3

Histograms showing changes in values of echocardiographic variables between baseline and follow up echocardiograms, stratified into high and low baseline heart rate (BHR) groups (panels A and B) and into atrial fibrillation (AF) and sinus rhythm (SR) groups (panels C and D). Data are plotted as means with standard errors. AF, atrial fibrillation; LVESD, left ventricular end systolic dimension; SR, sinus rhythm. *p < 0.1 v baseline; ***p < 0.005 v baseline; ****p < 0.0001 v baseline. There were no significant differences between groups for any of the measured variables.