Absence of Documented Standard Modifiable Cardiovascular Risk Factors Among Catheterized Admissions in Bangladesh: Frequency and Coronary Angiographic Phenotype in a 20‐Year Registry Study

Background and Aims: Coronary artery disease may occur without standard modifiable cardiovascular risk factors (SMuRFs), but the frequency and angiographic phenotype of such presentations in South Asian catheterization cohorts remain uncertain. We estimated registry-defined SMuRF-less frequency, tested alternative dyslipidaemia definitions, and compared angiographic phenotypes by SMuRF status. Methods: We conducted a retrospective, single-centre, registry-based cross-sectional analysis of 51,864 admissions with matched catheterization records at a Bangladeshi tertiary cardiac centre from 2005 to 2024. Admissions were classified as SMuRF-less when no qualifying hypertension, diabetes, smoking, or dyslipidaemia was documented or identified; dyslipidaemia reflected a documented diagnosis or qualifying lipid measurement. Documented-only and statin-inclusive definitions were sensitivity analyses. We calculated unadjusted prevalence ratios (PRs) and 95% confidence intervals (CIs). Results: Under the primary definition, 3172 admissions (6.1%) were SMuRF-less, compared with 6.5% under the documented-only definition and 1.6% under the statin-inclusive definition. Among admissions with a classifiable angiographic phenotype, SMuRF-less admissions more frequently had normal coronary arteries (24.9% vs. 10.7%; PR, 2.34; 95% CI, 2.18-2.50) and less frequently had obstructive coronary artery disease (56.6% vs. 71.2%; PR, 0.79; 95% CI, 0.77-0.82). Among admissions with obstructive disease, multivessel disease was less frequent (49.6% vs. 57.8%; PR, 0.86; 95% CI, 0.82-0.90), whereas recorded intracoronary thrombus was more frequent (5.3% vs. 3.2%; PR, 1.65; 95% CI, 1.33-2.04). Of 6635 ST-elevation myocardial infarction admissions, 355 (5.4%) were SMuRF-less; 318 (89.6%) had obstructive disease. Conclusion: Registry-defined SMuRF-less admissions, reflecting absence of documented qualifying factors rather than prospectively verified biological absence, were uncommon, and their estimated frequency depended on risk-factor ascertainment. Although their recorded angiographic burden was generally lower, obstructive disease remained common, particularly in ST-elevation myocardial infarction. The absence of documented SMuRFs should not provide clinical reassurance. Prospective patient-level studies with standardized risk-factor assessment and longitudinal follow-up are needed.