Atrioventricular block in acute coronary syndrome: Portuguese experience
Authors: Santos H , Santos M , Almeida I , Miranda H , Sa C , Chin J , Almeida S , Sousa C , Almeida L 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

OnBehalf
Portuguese Registry of Acute Coronary Syndromes

Background
The atrioventricular block (AVB) occurrence in acute coronary syndrome (ACS) is a potentially life-threatening complication, that demand a rapid and efficient response regarding reperfusion time and rhythm stabilization.

Objective
Evaluate the impact and prognosis of AVB in ACS patients, as well as predictors of AVB.

Methods
Multicenter retrospective study, based on the Portuguese Registry of ACS between 1/10/2010-3/05/2020. Patients were divided into two groups: A – patients without AVB, and B – patients that presented AVB. Were excluded patients without a previous cardiovascular history or clinical data regarding AVB occurrence. Logistic regression was performed to assess predictors of AVB in ACS patients.

Results
From 32157 patients, 23774 was included, 23148 in group A (97.4%) and 626 in group B (2.6%). Both groups were similar regarding initial symptons until first medical contact (p = 0.410), smoker status (p = 0.222), arterial hypertension (p = 0.776), diabetes mellitus (p = 0.508), peripheral artery disease (p = 0.479), chronic kidney disease (p = 0.467) and re-infarction during the hospitalization for ACS (p = 0.145). Group A had higher body mass index (27.4 ± 4.4 vs 26.9 ± 4.6, p = 0.005), dislipidaemia (59.6 vs 51.4%, p &lt; 0.001), coronary artery disease (18.9 vs 13.0, p &lt; 0.001), heart rate (78 ± 19 vs 65 ± 25, p &lt; 0.001), systolic blood pressure (139 ± 29 vs 119 ± 32, p &lt; 0.001) and left ventricular ejection fraction (LVEF) &gt;50% (60.1 vs 51.7%, p &lt; 0.001). On the other hand, group B was elderly (66 ± 13 vs 71 ± 13, p &lt; 0.001), female (27.4 vs 32.4%, p &lt; 0.001), previous stroke (6.9 vs 10.9%, p &lt; 0.001), neoplasia (4.9 vs 6.8%, p = 0.031), ST-segment elevation myocardial infarction (46.2 vs 75.4%, p &lt; 0.001), syncope as major symptom (1.3 vs 10.0%, p &lt; 0.001), Killip-Kimball class &gt; I (15.4 vs 31.6%, p &lt; 0.001), multivessel diasease (52.1 vs 61.4%, p &lt; 0.001), heart failure complication (15.5 vs 40.6%, p &lt; 0.001), cardiogenic shock complication (3.8 vs 24.6%, p &lt; 0.001), new-onset of atrial fibrillation (4.2 vs 14.1%, p &lt; 0.001), ACS mechanical complication (0.6 vs 3.2%, p &lt; 0.001), sustained ventricular tachycardia during ACS hospitalization (1.3 vs 10.0%, p &lt; 0.001), cardiac arrest (2.7 vs 13.3%, p &lt; 0.001), stroke complication (0.6 vs 1.9%, p &lt; 0.001) and hospitalization death (3.5 vs 19.0%, p &lt; 0.001). Logistic regression revealed that female gender (odds ratio (OR) 1.422, p = 0.015, confidence interval (CI) 1.072-1.885), age ≥75 years old (OR 1.560, p = 0.002, CI 1.174-2.073), heart rate &lt;60 (OR 6.692, p &lt; 0.001, CI 5.180-8.644) and Killip-Kimball class &gt; I (OR 3.264, p &lt; 0.001, CI 2.446-5.356) were predictors of AVB in ACS patients.

Conclusions
Female gender, age ≥75 years old, heart rate &lt;60 and Killip-Kimball class &gt; I were predictors of AVB in ACS patients.