STOCKHOLM — A significant drop in left ventricular volume following implantation of a cardiac resynchronization device predicts the best clinical outcome in patients with severe heart failure, according to data from 141 patients.
“Left ventricular remodeling is an objective measure of efficacy” after cardiac resynchronization therapy (CRT), Cheuk-Man Yu, M.D., said at the annual congress of the European Society of Cardiology.
He reviewed the outcomes of patients with New York Heart Association class III or IV heart failure and dilated cardiomyopathy who received a CRT device at the Prince of Wales Hospital at the Chinese University in Hong Kong.
All patients had an echocardiogram at baseline and at 3–6 months after the CRT device was placed to assess the impact of CRT on cardiac size and function.
After an average follow-up of almost 2 years (695 days), 22 (15.6%) of the patients had died, mostly because of heart failure (9 patients) or cardiac arrest (6 patients). In addition, 19 patients were hospitalized for heart failure, and 21 patients were hospitalized for other cardiovascular disease.
An analysis of the echocardiographic changes that occurred between CRT implantation and the 3–6 month exam showed that patients who died during the first 1.9 years after treatment had significantly less early benefit from CRT, compared with patients who survived, reported Dr. Yu, chief of the division of cardiology at Prince of Wales Hospital.
For example, in patients who survived the follow-up period, left ventricular end-systolic volume fell by an average of 19.8% during the first few months of CRT, whereas in patients who died during follow-up, the average drop in end-systolic volume was 5.9%.
In a multivariate analysis, change in left ventricular end-systolic volume was the only significant predictor of long-term survival. Clinical parameters measured during the first few months after the start of CRT did not predict survival.
The reduction of end-systolic volume by less than 10% after CRT allowed for the prediction of all-cause death during the 1.9 years of follow-up, with a sensitivity of 70% and a specificity of 70%, said Dr. Yu. It also allowed for the prediction of death from a cardiovascular cause, with a sensitivity of 87% and a specificity of 69%.
Two factors seemed primarily responsible for limiting the reduction in left ventricular volume by CRT: suboptimal lead placement and a failure by CRT to reduce the QRS interval to less than 120 milliseconds, Dr. Yu said.