# Coronary Angiographic Profile and Incidence of Coronary Artery Disease in Patients Undergoing Permanent Pacemaker Implantation for Conduction Abnormalities

## TL;DR

This study finds that half of patients getting pacemakers for heart rhythm issues also have coronary artery disease, with diabetes and high blood pressure as key risk factors.

## Contribution

The study provides new insights into the prevalence of silent coronary artery disease in pacemaker patients and identifies diabetes and hypertension as significant predictors.

## Key findings

- Half of the patients undergoing pacemaker implantation had coronary artery disease (CAD), with 28% having obstructive CAD.
- Diabetes mellitus and hypertension were significantly associated with obstructive CAD in these patients.
- Coronary angiography revealed that the left anterior descending artery was most commonly affected by CAD.

## Abstract

Background: Symptomatic bradyarrhythmias necessitating permanent pacemaker implantation (PPI) predominantly affect elderly individuals with multiple cardiovascular risk factors. Coronary artery disease (CAD) is a known cause of conduction disturbances, and ischemia affecting the atrioventricular (AV) node or His bundle may present as bradyarrhythmias. However, CAD can be clinically silent, and traditional risk factors often correlate with the presence of coexistent CAD. The prevalence of CAD among pacemaker recipients has been shown to vary widely. Our study aims to assess the incidence of CAD in patients undergoing PPI for conduction abnormalities and identify clinical predictors of CAD in this population.

Aim: This study aims to determine the coronary angiographic profile of patients undergoing permanent pacemaker insertion for conduction abnormalities to assess the incidence and characterization of CAD.

Methods: We conducted a prospective, observational, single-center study at a tertiary care institute, enrolling adult patients with symptomatic bradyarrhythmias (high-grade AV block or sinus node dysfunction) undergoing PPI. We excluded patients with acute coronary syndrome and those with conditions that would preclude invasive procedures. Clinical and demographic data were collected, including a detailed history of coronary risk factors. All patients underwent coronary angiography prior to or during PPI to assess the presence and severity of CAD. CAD was classified as non-obstructive (plaque <50% stenosis) or obstructive (≥50% stenosis). Statistical analysis was performed using chi-square and Student’s t-test, with p<0.05 considered significant.

Results: Among 50 patients (mean age 67 ± 12.5 years), 25 (50%) had normal coronary findings, while 25 (50%) had CAD. Of those with CAD, 11 (22%) had non-obstructive plaques, and 14 (28%) had obstructive CAD. The most common coronary artery involved was the left anterior descending (LAD) artery. Seven patients with obstructive CAD underwent percutaneous coronary intervention (PCI), and seven received optimal medical therapy. Risk factors such as diabetes mellitus (p=0.015) and hypertension (p=0.005) were significantly associated with the presence of obstructive CAD. Echocardiographic findings such as left ventricular ejection fraction (LVEF) and regional wall motion abnormalities (RWMA) were not reliable predictors of CAD presence.

Conclusions: Our study demonstrates that CAD is common among patients undergoing PPI, with a significant proportion having obstructive CAD despite being asymptomatic. Diabetes and hypertension were identified as key risk factors for CAD in this population. The findings suggest that coronary angiography should be considered routinely in high-risk patients undergoing PPI, as it can identify silent CAD and guide therapeutic decisions, ultimately improving prognosis.