Effect of smoking on prognosis in patients with non-ischaemic cardiomyopathy

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Cigarette Smoking is a well-known risk factor for increased cardiovascular morbidity and mortality, by causing inflammation, thrombosis, oxidation of low-density lipoprotein cholesterol, and is associated with increased myocardial fibrosis as late gadolinium enhancement on cardiac MRI. Myocardial fibrosis is a powerful factor for predicting arrhythmic deaths and mortality in heart failure patients. Little data is available on effect of smoking on non-ischaemic cardiomyopathy (NICMP). We hypothesize that smoking has an adverse effect on prognosis of patients with NICMP. Methods This study included 447 patients with heart failure and reduced left ventricular ejection fraction (LVEF <40%) due to non-ischemic cardiomyopathy, all have coronary angiogram to exclude significant coronary artery disease (>70% stenosis). Mean follow-up duration of 6.34 ± 4.16 years. Composite endpoints include death, ventricular arrhythmia (VA) or hospitalisations for heart failure. Data were analysed using STATA version 16.0. Cox regression was used to explore the relationships between smoking and composite endpoints. Statistical significance was denoted as p<0.05. Results Mean age 63.07 ± 14.19 years, male patients 314 (72%). Mean LVEF 22.89 ± 8.50%. Patients with diabetes mellitus 38%, hypertension 76%, atrial fibrillation 38%, stroke 9%. LDL 2.78 ± 1.04 mmol/l, HbA1c 6.56 ± 1.62%. Patients taking ivabradine 9%, b-blocker 88%, Angiotensin inhibitors/Angiotensin Receptor Blocker 66%, Sacubitrial/ Valsartan 26%, spironolactone 57%, SGLT-2 inhibitor 9%. 40 patients (9%) received device therapy (AICD and Cardiac resynchronization therapy), 19% secondary prevention, 81% for primary prevention. Smoking (100 cigarette pack year) increased the hazards for composite endpoint by 2.39, [HR (95% CI): 1.074, 5.325; p = 0.033]. Conclusion Smoking increases the hazards for composite endpoints in patients with NICMP and smoking cessation is recommended.