Therapeutic efficacy of diltiazem in 41 patients with life-threatening coronary artery spasm:a retrospective cohort study

Abstract Background Coronary Artery Spasm(CAS) is defined as transient abnormal contraction of epicardial coronary arteries and/or coronary microvasculature due to multifactorial causes, resulting in partial or complete vascular occlusion and subsequent myocardial ischaemia[1]. The precise aetiopathogenesis of CAS remains incompletely elucidated but is hypothesised to involve endothelial dysfunction , hyperreactivity of vasoconstrictive responses, oxidative stress, and autonomic dysregulation [5]. Purpose A total of ‌41 patients were collected in the analysis to evaluate the therapeutic outcomes and safety profile of intravenous diltiazem in resuscitating patients with refractory, life-threatening CAS, thereby informing evidence-based emergency management strategies. Methods A retrospective cohort analysis was conducted of ‌41 consecutive patients‌ presenting with life-threatening CAS complicated by high-mortality-risk clinical events, managed within the Coronary Care Unit (CCU) of our institution between October 2012 and July 2024.All patients underwent invasive coronary angiography(ICA) or contrast-enhanced coronary computed tomography angiography (CCTA) to confirm CAS, with diagnostic adjudication strictly adhering to:‌European Society of Cardiology (ESC) criteria for vasospastic anginaThe clinical characteristics, coronary imaging features, comorbidities, resuscitative measures, and treatment outcomes were analysed. Results Over 60% of chest pain episodes were non-exertional, while exertional triggers accounted for 36.6%. Other identified precipitants included alcohol consumption (4.9%), emotional stress (4.9%), post-procedural stress (7.3%), and defecation (9.8%); Concomitant cardiac events included loss of consciousness (43.9%), sustained ventricular tachycardia/fibrillation (VT/VF) (41.5%), Mobitz type II/III-degree atrioventricular block(AVB) (29.27%), and cardiac arrest (17.1%). Refractory cases underwent protocolized diltiazem administration (2–5 mg intravenous bolus repeated at 4–6 intervals, followed by 5–15 mg/kg/h titrated infusion, maximum 50 mg/kg/h). Critically, diltiazem infusion maintained hemodynamic stability within 20-30 minutes in 92.7% of cases, with adjunctive nitroglycerin required in 22.5% of patients‌. Among 41 hospitalized CAS patients, diltiazem-based therapy achieved 95.12% survival-to-discharge rate, notwithstanding two mortality events secondary to irreversible multiorgan failure. Notably, zero instances of hemodynamic compromise were documented during acute-phase infusion or longitudinal oral maintenance therapy. Alarmingly, two fatalities directly correlated with non-compliant diltiazem discontinuation, definitively establishing its therapeutic indispensability in CAS management. Conclusion Diltiazem demonstrated efficacy and safety in managing malignant tachyarrhythmias or bradyarrhythmias secondary to coronary artery spasm, including cardiac arrest, sustained VT/VF, and III° AVB.figure1  figure2