Secondary pulmonary hypertension is a marker of advanced heart failure (HF) that confers a poor prognosis. Consecutive patients from 2004 through 2005 who underwent echocardiographic assessments of systolic pulmonary arterial pressure (SPAP) before the implantation of cardiac resynchronization therapy defibrillators were included. Patients were divided into tertiles according to baseline SPAP. Patients in the lowest (group I, 20 to 29 mm Hg) and highest (group III, 45 to 88 mm Hg) tertiles were compared for the end points or death or transplantation and for HF hospital admission. Two hundred seventy patients were evaluated, of whom 95% were Caucasians and 91% men. The mean age was 66.5 +/- 11.6 years, the mean QRS duration was 155 +/- 30 ms, the mean left ventricular ejection fraction was 22.6 +/- 9.7%, and the mean New York Heart Association functional class was 3.0 +/- 0.4. In a multivariate model, death or transplantation was significantly more likely in group III (hazard ratio 2.62, 95% confidence interval 1.1 to 6.4, p = 0.036), as was HF admission (hazard ratio 6.35, 95% confidence interval 2.6 to 15.8, p <0.001). In patients with follow-up echocardiographic assessments, a reduction in SPAP was a significant predictor of freedom from the combined end point (hazard ratio 0.29, 95% confidence interval 0.12 to 0.76, p = 0.011). In conclusion, elevated baseline SPAP in patients who underwent cardiac resynchronization therapy is an independent predictor of all-cause mortality or transplantation and HF admission. A decrease in SPAP on follow-up echocardiography is an independent positive prognostic marker.