Abstract 18299: Prevalence of and Correlates with QRS Prolongation in Heart Failure with Preserved Ejection Fraction: Data from the KaRen Study

Background: QRS ≥ 120 ms is present in 1/3 of patients with heart failure with reduced ejection fraction, favorably treated with cardiac resynchronization therapy. In heart failure with preserved ejection fraction (HFPEF), the prevalence of and correlates with QRS prolongation are largely unknown. Methods: KaRen is a multicenter prospective registry of HFPEF (ClinicalTrials.gov NCT00774709 ). Inclusion criteria are Framingham symptoms and signs of heart failure together with NT-proBNP >300 ng/L and LVEF ≥45%. In patients with sinus rhythm and with atrial fibrillation / flutter (AF), the prevalence of and association between QRS prolongation and clinical characteristics was assessed with uni- and multivariable linear regression, with 10 clinical variables, ejection fraction, and EKG parameters (10 in sinus rhythm; 6 in AF), using backward step-wise selection based on p < 0.10. Results: We studied 382 patients, mean (SD) age 77 (9) years, 56% women. QRS < 120 ms, 120-149 ms, ≥ 150 ms, LBBB, and ventricular-paced EKG was present in 78, 11, 3, 3 and 8% respectively. One-hundred twenty-six patients (35%) had AF. AF was not associated with QRS width. The table lists variables independently associated with QRS in ms, their baseline values and Beta coefficients, separately among patients in sinus rhythm and AF, excluding ventricular-paced patients. Conclusions: In HFPEF, QRS prolongation and LBBB are less common than in reduced ejection fraction. QRS prolongation is associated with other EKG pathology and with B-blocker use. The rarely measured parameter “P-wave duration” may reflect the same underlying global conduction delay as QRS duration.