Biomedical subjects

Mode Selection Trial (MOST) Investigators

Publications and source records attributed to Mode Selection Trial (MOST) Investigators.

3 recordsLinked to original sources

PubMed2005

Association of prolonged QRS duration with death in a clinical trial of pacemaker therapy for sinus node dysfunction.

BACKGROUND: Prolonged QRS duration (QRSd) is an important prognostic indicator for death and heart failure hospitalization in patients with systolic heart failure. The relationship of baseline QRSd to death and heart failure hospitalization in patients with sinus node dysfunction who require pacemaker therapy is unknown. METHODS AND RESULTS: Baseline QRSd from 12-lead ECGs before pacemaker implantation were analyzed in the Mode Selection Trial (MOST), a 6-year, 2010-patient randomized trial of dual-chamber versus ventricular pacing in sinus node dysfunction. Baseline QRSd was > or =120 ms in 23.4% of patients and was associated with older age, lower ejection fraction, cardiomyopathy, and prior heart failure. Adjusted Cox models demonstrated baseline QRSd > or =120 ms was a strong independent predictor of death (hazard ratio [95% CI] 1.35 [1.07, 1.70], P=0.010) but not heart failure hospitalization. The risk of death increased with increased QRSd from 60 to 120 ms (P=0.002 and hazard ratio [95% CI] 1.14 [1.05, 1.23] for 10-ms increase in this range) after adjustment for other death predictors. CONCLUSIONS: Baseline QRSd > or =120 ms was associated with increased risk of death during pacemaker therapy for sinus node dysfunction.

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PubMed2005

Heart failure hospitalization is more common in pacemaker patients with sinus node dysfunction and a prolonged paced QRS duration.

OBJECTIVES: The purpose of this study was to determine whether a prolonged paced QRS duration increases the risk of cardiac dysfunction. BACKGROUND: Right ventricular apical pacing mimics left bundle branch block, results in a prolonged QRS duration of variable duration, and causes ventricular desynchronization. METHODS: In the Mode Selection Trial (MOST), QRS duration was measured in patients who had at least one paced ventricular complex recorded on 12-lead ECG within 3 months of enrollment (early) and after 9 months (late). Clinical endpoints including heart failure hospitalization, mortality, and atrial fibrillation were analyzed. A total of 1,026 patients were included in the analysis. Median age was 75 years (25th, 75th percentiles = 69, 80) and median ejection fraction prior to implant was 55% (45, 60). The cumulative percent ventricular pacing (DDDR and VVIR) was 81% over a median follow-up of 33 months. During period, 123 patients had heart failure hospitalization, 197 died, and 261 patients had atrial fibrillation. RESULTS: Cox proportional hazards models demonstrated that paced QRS duration was a strong predictor of heart failure hospitalization (hazard ratio 1.15; 95% confidence interval 1.07,1.23) for each 10-ms increase in paced QRS duration (P = .001). The increased risk was unaffected by adjustment for other known predictors of heart failure hospitalization in the study. Paced QRS duration was not significant for mortality (P = .41) or atrial fibrillation (P = .20) when baseline QRS duration and other predictors were included. CONCLUSIONS: Paced QRS duration is a significant, independent predictor of heart failure hospitalization in patients with sinus node dysfunction. A very long paced QRS duration is associated with increased heart failure hospitalization.

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PubMed2003

Death in patients with permanent pacemakers for sick sinus syndrome.

BACKGROUND: Although more than one million patients in the United States have permanent pacemakers, little is known about their cause of death. We evaluated the cause of death in 404 patients who died in the Mode Selection Trial (MOST). METHODS: In MOST, patients received a dual-chamber pacemaker randomly programmed to either dual-chamber or ventricular pacing. The circumstances surrounding each death were reviewed by a clinical events committee, which used prospectively defined criteria to adjudicate the cause of death. RESULTS: A total of 2010 patients with a median age of 74 years were included. After a median follow-up of 33 months, 404 (20%) patients died, including 198 (49%) of noncardiac causes and 143 (35.4%) of cardiac causes. In 63 patients, the cause of death was unknown. Independent predictors of death through the use of a multivariable analysis were (1) demographic factors including age, male sex, and weight; (2) clinical factors including prior myocardial infarction, cardiomyopathy, New York Heart Association class III/IV, and the Charlson Comorbidity Index; and (3) scores from two measures of functional status, the Karnofsky Score and the Mini-Mental State Examination. Independent predictors of cardiovascular death were similar. CONCLUSIONS: Patients treated with permanent pacemakers for sinus node dysfunction are elderly and have a substantial mortality rate, with more than half the classifiable deaths being noncardiac. Baseline demographic variables and scores from quality-of-life measures can identify patients with the highest risk of death.

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