The study was conducted to determine whether the midrange ejection fraction (mrEF) is associated with increased risk of deterioration of cardiac function (DCF) after dual chamber permanent pacemaker (PPM) implantation.
We performed a prospective cohort study of relevance in patients with EF ≥ 40% and indications for PPMs. Patient characteristics were recorded at baseline and 1 day, 1 month, 3 months, and 6 months after PPM implantation with leads placed in the right ventricular apex. These included clinical symptoms, signs, biochemical parameters, BNP, echocardiography and ECG parameters, and pacing-related parameter changes. The patients were followed-up for 6 months. Univariate and multivariable Cox regression analyses were performed.
A total of 879 patients were included, aged 35 to 88 years (mean age 67.2 ± 9.6); a total of 81 patients (9.2%) developed DCF after PPM implantation, including LVEF < 40% (57 cases) and increased NYHA class (24 cases). Cox models demonstrated that age ≥ 75 years (HR 2.273 [95% CI, 1.541-3.626]), OMI (HR 2.078 [95% CI, 1.275-3.604]), mrEF (HR 2.762 [95% CI, 1.558-4.769]), moderate mitral regurgitation (HR 2.819 [95% CI, 1.604-4.153]), and right ventricular pacing ≥ 50% (HR 2.311 [95% CI, 1.478-3.937]) were strong predictors for DCF, and NT-proBNP > 1000 ng/L and paced QRS duration ≥ 180 ms were also the independent predictors of DCF.
MrEF was associated with increased risk of deterioration of cardiac function after PPM implantation. Moderate mitral regurgitation and increased NT-proBNP levels are also potential independent predictors for deterioration of cardiac function after PPM implantation.