Initial heart rate and cardiovascular outcomes in patients presenting with acute coronary syndrome

Abstract

Objectives: To assess the impact of on-admission heart rate (HR) in patients presenting with acute coronary syndrome (ACS).

Methods: Data were collected retrospectively from the second Gulf Registry of Acute Coronary Events. Patients were divided according to their initial HR into: (I: < 60, II: 60–69, III: 70–79, IV: 80–89 and V: ≥ 90 bpm). Patients’ characteristics and hospital and one- and 12-month outcomes were analyzed and compared.

Results: Among 7939 consecutive ACS patients, groups I to V represented 7%, 13%, 20%, 23.5%, and 37%, respectively. Mean age was higher in groups I and V. Group V were more likely males, diabetic and hypertensive. ST-elevation myocardial infarction was the main presentation in groups I and V. Reperfusion therapies were less likely given to group V. Beta blockers were more frequently prescribed to group III in comparison to groups with higher HR. Groups I and V were associated with worse hospital outcomes. Multivariate analysis showed initial tachycardia as an independent predictor for heart failure (OR 2.2; 95%CI: 1.39–3.32), while bradycardia was independently associated with higher one-month mortality (OR 2.0; 95%CI: 1.04–3.85)

Conclusion: The majority of ACS patients present with tachycardia. However, low or high HR is a marker of high risk that needs more attention and management.

Keywords::

• Acute coronary syndrome
• bradycardia
• tachycardia
• heart rate
• mortality

Acknowledgement

The authors thank the staff in all the participating centers for their invaluable cooperation. Special thanks to Zenaida Ramoso and Kazi Nur Asfina for data coordination and secretarial assistance, and also to the physicians who participated in this registry.

Funding

Gulf RACE is a Gulf Heart Association (GHA) project and was financially supported by the GHA, Sanofi Aventis, and the College of Medicine Research Center at King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia. The sponsors had no role in study design, data collection, data analysis, writing of the report, or submission of the manuscript. Ethical approvals were obtained prior to the study.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.