CHICAGO – Phased withdrawal of guideline-directed medical therapy in patients who seemed to have recovered from dilated cardiomyopathy resulted in relapses in 40% of patients within 6 months in the trial.
The clinical implications of this small pilot randomized trial are clear: “Withdrawal of therapy should not usually be attempted, at least until we can predict who’s going to relapse and who’s not,” Brian P. Halliday, MD, PhD, said at the American Heart Association scientific sessions.
“Improvement in function represents remission rather than permanent recovery for many patients,” added Dr. Halliday of Imperial College London.
The study was performed to address a question that arises with increasing frequency in clinical practice as a result of the impressive advances in heart failure therapy in recent years, he said. “Patients frequently come to us in clinic and ask us, ‘Do I need to continue to take these medications forever?’ They’re frequently young, and they want to know if they really need to be subject to 40 or 50 years of medication. Some are concerned about side effects, others are interested in pregnancy, and then there is the financial cost.”
Simultaneously published in The Lancet,was a single-center, open-label study of 51 patients who had prior dilated cardiomyopathy (DCM) and a median left ventricular ejection fraction (LVEF) of 25% at the time of diagnosis 4.9 years earlier and who subsequently recovered in response to therapy. That is, they became symptom-free with an LVEF greater than 50%, a normal left ventricular end diastolic volume index, and a reassuringly low median N-terminal pro b-type natriuretic peptide (NP-pro-BNP) level of 72 ng/L.
For the study, 25 patients were randomized to phased withdrawal of their heart failure drugs over a 16-week period: First they reduced or stopped loop diuretics, then mineralocorticoid antagonists, then beta-blockers, and finally their ACE inhibitor or angiotensin receptor blocker. The other 26 participants continued therapy during the first 6 months of the study, then 25 of the 26 crossed over to phased withdrawal. The outlier didn’t cross over because of atrial fibrillation.
The primary endpoint was relapse of DCM within 6 months of the start of the study. Relapse was defined as either a drop in LVEF of more than 10% to a level below 50%, at least a doubling of NT-pro-BNP to greater than 400 ng/L, clinical evidence of heart failure, or a greater than 10% increase in LV end diastolic volume as assessed by cardiac MRI.
During the first half of the study, 11 of 25 patients (44%) relapsed during or after medication withdrawal. None of the controls relapsed. In the crossover phase, 9 of 25 patients (35%) relapsed in response to treatment withdrawal. Of the 20 patients who relapsed, 13 did so within 16 weeks of beginning medication withdrawal. Indeed, most patients relapsed within 8 weeks of their last medication. Ten of the twenty fulfilled multiple criteria for relapse.
Medication withdrawal was accompanied not only by a mean 9.5% reduction in LVEF, compared with baseline, but by a 15.4-bpm rise in heart rate, a 7.0–mm Hg increase in diastolic blood pressure, and 5.1-point deterioration in Kansas City Cardiomyopathy Questionnaire scores, demonstrating that what happened off treatment was true DCM recurrence and not simply an imaging artifact.