Impact of left ventricular size on pharmacologic reverse remodeling in heart failure

Although medical therapy may normalize echocardiographic left ventricular (LV) systolic function in selected patients with cardiomyopathy, other patients experience no change or a further deterioration in heart failure remodeling. Our aim was to determine what clinical or echocardiographic parameters predict a beneficial therapeutic response.

We prospectively followed biannual clinical and echocardiographic assessments in 215 patients. Forty-six of these patients ("Nonresponders") experienced no change or a decline in LV ejection fraction at 6 months. Of the 148 patients who improved LV function, 21 ("Responders") normalized LV systolic function at 6 months. Only Responders (n = 21) and Nonresponders (n = 46) were compared.

On average, these 67 patients were 54 +/- 12 years old with 4.5 +/- 3.3 years of heart failure. At 6 months, following up-titration of angiotensin-converting enzyme inhibitors and nitrates, Responder LV ejection fraction rose from 22 +/- 6 to 50 +/- 5% with improvement in New York Heart Association classification (2.6 +/- 0.8 to 1.5 +/- 0.8, p = 0.001). These patients had significantly more favorable clinical and echocardiographic outcomes versus Nonresponders despite comparable medical therapy. All baseline demographic, clinical, and echocardiographic variables were equivalent, except for initial LV end-diastolic diameter which differentiated Nonresponders (7.1 +/- 0.7 cm) from Responders (6.1 +/- 0.8 cm), p = 0.007.

Thus, although heart failure therapy improves LV systolic function in a majority of patients, with normalization in up to 10% of patients, significant LV enlargement may render remodeling unresponsive to pharmacologic intervention, with a potential future need for alternative mechanical or surgical intervention.