Background -Cardiac resynchronization therapy(CRT) is an effective therapy for patients with moderate to severe heart failure and prolonged QRS duration. The purpose of this study was to determine whether reverse left...Background -Cardiac resynchronization therapy(CRT) is an effective therapy for patients with moderate to severe heart failure and prolonged QRS duration. The purpose of this study was to determine whether reverse left ventricular(LV) remodeling and symptomatic benefit from CRT were sustained at 12 months, and if so, in what proportion of patients this occurred. Methods and Results -Serial Doppler echocardiograms were obtained at baseline and 6 and 12 months after CRT in 228 patients enrolled in the Multicenter InSync Randomized Clinical Evaluation(MIRACLE) trial. Measurements were made of LV end-diastolic(EDV) and end-systolic(ESV) volumes, ejection fraction, LV mass, severity of mitral regurgitation(MR), peak transmitral velocities during early(E wave) and late(A wave) diastolic filling, and myocardial performance index. At both 6 and 12 months, respectively, CRT was associated with reduced LV EDV(P< 0.0001 and P=0.007) and LV ESV(P< 0.0001 and P< 0.0001), improved ejection fraction(P< 0.0001 and P< 0.0001), regression of LV mass(P=0.012 and P< 0.0001), and reduced MR(P< 0.0001 and P< 0.0001). LV filling time, transmitral E/A ratio, and myocardial performance index all improved at 12 months compared with baseline(P< 0.001, P=0.031, and P< 0.0001). Reverse LV remodeling with CRT occurred in more patients at 6 than at 12 months(74%versus 60%, respectively; P< 0.05) and was greater in patients with a nonischemic than an ischemic etiology. Conclusions -Reverse LV remodeling and symptom benefit with CRT are sustained at 12 months in patients with New York Heart Association class III/IV heart failure but occur to a lesser degree in patients with an ischemic versus a nonischemic etiology, most likely owing to the inexorable progression of ischemic disease.展开更多
Background: Based on current patient selection criteria, a significant proportion of recipients of cardiac resynchronization therapy(CRT) do not respond to treatment. The purpose of this analysis is to identify predic...Background: Based on current patient selection criteria, a significant proportion of recipients of cardiac resynchronization therapy(CRT) do not respond to treatment. The purpose of this analysis is to identify predictors and characterize the timing of response to CRT in patients with advanced heart failure. Methods: Patients randomized to receive CRT in the MIRACLE and MIRACLE-ICD trials, designed to assess the benefit of CRT compared with standard medical therapy in patients with advanced heart failure, left ventricular ejection fraction< 0.35, and QRS ≥130 milliseconds, were included for this analysis. Patients with an improvement of ≥1 New York Heart Association(NYHA)class from baseline to the 6-month follow-up were considered responders and those who had no change or worse NYHA class or died were classified as nonresponders. Responders were subdivided into early(within 1-3 months) and late(6 months). Results: One hundred forty-three(64%) of 224 and 190(61%) of 313 patients in the MIRACLE and MIRACLEICD trials, respectively, responded to therapy, with 81(57%) of 143 and 100(53%) of 190 responding early. Several but differing factors predicted CRT response and timing in the two trials with a high sensitivity(89%-90%) but, owing to a low specificity(31%-49%), a modest predictive accuracy(66%-75%). Conclusions: Based on improvement of ≥1 NYHA class, less than two thirds of patients enrolled in the MIRACLE or MIRACLE-ICD trials responded to CRT, with just more than half responding within the first month. Several factors predicted CRT response and timing, but given their modest predictive accuracy, comparable for both studies, additional methods for selecting candidates most likely to benefit from CRT are needed.展开更多
文摘Background -Cardiac resynchronization therapy(CRT) is an effective therapy for patients with moderate to severe heart failure and prolonged QRS duration. The purpose of this study was to determine whether reverse left ventricular(LV) remodeling and symptomatic benefit from CRT were sustained at 12 months, and if so, in what proportion of patients this occurred. Methods and Results -Serial Doppler echocardiograms were obtained at baseline and 6 and 12 months after CRT in 228 patients enrolled in the Multicenter InSync Randomized Clinical Evaluation(MIRACLE) trial. Measurements were made of LV end-diastolic(EDV) and end-systolic(ESV) volumes, ejection fraction, LV mass, severity of mitral regurgitation(MR), peak transmitral velocities during early(E wave) and late(A wave) diastolic filling, and myocardial performance index. At both 6 and 12 months, respectively, CRT was associated with reduced LV EDV(P< 0.0001 and P=0.007) and LV ESV(P< 0.0001 and P< 0.0001), improved ejection fraction(P< 0.0001 and P< 0.0001), regression of LV mass(P=0.012 and P< 0.0001), and reduced MR(P< 0.0001 and P< 0.0001). LV filling time, transmitral E/A ratio, and myocardial performance index all improved at 12 months compared with baseline(P< 0.001, P=0.031, and P< 0.0001). Reverse LV remodeling with CRT occurred in more patients at 6 than at 12 months(74%versus 60%, respectively; P< 0.05) and was greater in patients with a nonischemic than an ischemic etiology. Conclusions -Reverse LV remodeling and symptom benefit with CRT are sustained at 12 months in patients with New York Heart Association class III/IV heart failure but occur to a lesser degree in patients with an ischemic versus a nonischemic etiology, most likely owing to the inexorable progression of ischemic disease.
文摘Background: Based on current patient selection criteria, a significant proportion of recipients of cardiac resynchronization therapy(CRT) do not respond to treatment. The purpose of this analysis is to identify predictors and characterize the timing of response to CRT in patients with advanced heart failure. Methods: Patients randomized to receive CRT in the MIRACLE and MIRACLE-ICD trials, designed to assess the benefit of CRT compared with standard medical therapy in patients with advanced heart failure, left ventricular ejection fraction< 0.35, and QRS ≥130 milliseconds, were included for this analysis. Patients with an improvement of ≥1 New York Heart Association(NYHA)class from baseline to the 6-month follow-up were considered responders and those who had no change or worse NYHA class or died were classified as nonresponders. Responders were subdivided into early(within 1-3 months) and late(6 months). Results: One hundred forty-three(64%) of 224 and 190(61%) of 313 patients in the MIRACLE and MIRACLEICD trials, respectively, responded to therapy, with 81(57%) of 143 and 100(53%) of 190 responding early. Several but differing factors predicted CRT response and timing in the two trials with a high sensitivity(89%-90%) but, owing to a low specificity(31%-49%), a modest predictive accuracy(66%-75%). Conclusions: Based on improvement of ≥1 NYHA class, less than two thirds of patients enrolled in the MIRACLE or MIRACLE-ICD trials responded to CRT, with just more than half responding within the first month. Several factors predicted CRT response and timing, but given their modest predictive accuracy, comparable for both studies, additional methods for selecting candidates most likely to benefit from CRT are needed.
