Elevated Estimated Pulmonary Artery Systolic Pressure is Associated with an Adverse Clinical Outcome in Patients Receiving Cardiac Resynchronization Therapy

BACKGROUND: A substantial percentage of patients with heart failure remain nonresponsive to cardiac resynchronization therapy (CRT). There is a paucity of information on the impact of baseline elevated pulmonary artery pressure on clinical outcome and on left ventricular reverse remodeling (LV-RR) after CRT. We sought to investigate the impact of elevated estimated pulmonary artery systolic pressure (ePASP) on clinical outcome and LV-RR after CRT. METHODS: This study retrospectively analyzed data from 68 subjects with standard indications for CRT over a 12-month period. Subjects were stratified into two groups based on the echocardiographic estimation of pulmonary artery pressure i.e., ePASP > or = 50 mmHg (n = 27) and ePASP < 50 mmHg (n = 41). Long-term response was measured as a combined endpoint of heart failure hospitalizations and all cause mortality at 12 months, and compared within the two groups using the Kaplan-Meier method. Follow up echocardiograms to assess for LV-RR were available in 51 subjects (mean duration 7.1 months). LV-RR was defined as any improvement in global systolic function with reduction in left ventricular internal diameter. RESULTS: The study population was composed of 24 women and 44 men (age, mean +/- SD; 70 +/- 11 years), with a decreased left ventricular ejection fraction ([25 +/- 9]%) and a wide QRS (171 +/- 54 ms). There were no significant differences in the clinical features between the high and low ePASP group. Subjects with ePASP > or = 50 mmHg had a significantly worse clinical outcome (Hazard ratio (95% CI), 2.0 (1.2-5.5), P = 0.02). Baseline ePASP was not predictive of LV-RR (P = 0.32). CONCLUSION: In patients receiving CRT, although elevated estimated pulmonary artery systolic pressure (ePASP > or = 50 mmHg) does not significantly impact LV reverse remodeling, it is associated with an adverse long-term outcome.