Clinical characteristics and outcomes of patients with acute myocardial Infarction without standard modifiable risk factors (SMuRFs).

Abstract

The etiology as well as the prevalence of acute myocardial infarction (AMI) in patients without history of standard modifiable risk factors (SMuRFs) remains unclear, especially in European populations. Simultaneously, evidence suggests that SMuRF-less patients may experience worse short-term outcomes after AMI. The "Beyond-SMuRFs" prospective observational study (NCT05535582) included 1011 consecutive patients with AMI in Greece, who underwent coronary angiography and had available data on clinical, laboratory and imaging parameters. SMuRF-less patients were defined as those who have no history of diabetes mellitus, dyslipidemia, hypertension or smoking. Multivariable logistic-regression and receiver operating characteristic (ROC) analyses were implemented to investigate potential predictors of SMuRF-less AMIs and their predictive ability. Kaplan-Meier curves and Cox-regresion analyses were used to compare all-cause mortality and the composite outcome of cardiovascular death or/and AMI/heart-failure (HF) re-hospitalization or/and stroke among patients with and without SMuRFs. Of 1011 patients with AMI (mean age 62.0 ± 11.8 years), 842 (83.2 %) had at least on SMuRF and 169 (16.7 %, 95 % CI: 14.5 %-19.1 %) were SMuRF-less patients. When patients with obesity or former smoking status were excluded from the SMuRF-less group, this number decreased to 140 (13.8 %, 95 % CI: 11.7 %-16.1 %). The multivariable logistic regression model showed that positive family history of AMI [adjusted Odds Ratios (aOR): 1.88 [1.26-2.80], p = 0.002), history of rheumatic/inflammatory disorders (3.31 [1.38-7.93], p = 0.007), major psychiatric disease (2.77 [1.24-6.19], p = 0.013) and drugs/alcohol abuse (4.45 [2.24-8.82], p < 0.001) were independently associated with the occurence of SMuRF-less AMI. The ROC area under the curve for this model was 0.64 ([0.58-0.69], p = 0.001) but was increased to 0.78 [0.73-0.83], p = 0.001), when patients with former smoking and obesity were not considered as SMuRF-less. Regarding the short-term (in-hospital and 30-day) outcomes, SMuRF-less patients exhibited higher rates of all-cause death [adjusted Hazard Ratio (aHR): 2.45 [1.36-4.41], p = 0.003 and 2.38 [1.32-4.31], p = 0.003, respectively] and the secondary composite outcome (aHR: 2.99 [1.65-5.09]; p = 0.001 and 2.75 [1.60-4.70]; p = 0.001, respectively). However, at long-term follow-up non-significant differences were observed. Positive family history, history of inflammatory or major psychiatric diseases, along with drug or alcohol abuse, were independently associated with SMuRF-less AMIs. SMuRF-less patients experienced worse short-term outcomes than patients with SMuRFs, which was not maintained at the long-term follow-up.