The absence of standard modifiable cardiovascular risk factors does not predict better outcomes in patients with acute coronary syndrome

Abstract

Introduction: The standard modifiable cardiovascular risk factors (SMuRFs), like diabetes mellitus, hyperlipidemia,hypertension and smoking, are central elements of the well-established European Society of Cardiology SCORE calculator. However, acute coronary syndromes (ACS) in SMuRF-less individuals are not uncommon. Purpose: Our study aimed to describe the population with and without SMuRFs attended for an ACS and study prognostic factors associated with mortality. Methods: We identified 1347 ACS patients without prior history of cardiovascular disease (ACS, cerebrovascular or peripheral artery disease) attended in our university hospital between 2009 and 2012 and examined the proportion of SMuRF-less patients as well as outcomes.The primary outcome was 5-year all-cause death. Results: Overall, the median age was 63 years, 73.4% were male and 52 patients (7%)had no SMuRFs. The most common SMuRF was hypertension (60%), followed by smoking (47%), dyslipidemia (48%) and diabetes mellitus (27%). In patients with and without SMuRFs there were no differences in the proportion of females (27% vs 28%), age (63.7 years [IQR 54-75] vs 62 years [IQR 53-71]), renal failure (4.7% vs 0%, p=0.159), prior heart failure (1.6% vs 1.9%, p=0.590) and pulmonary obstructive disease (11.3% vs 9.6%, p=0.707). SMuRF-less patients had substantially less angina in the previously month (1.9% vs 19.1%, p<0.001), were less treated previously with aspirin (3.9% vs 18.9%, p=0.006), betablockers (5.8% vs 16.6%, p=0.039)and ACEI/ARAII (0% vs 38.1%, p<0.001). Patients with SMuRFs presented significantly more frequently with a NSTEMI (63.1% vs 48.1%) and less frequently with STEMI (32.3% vs 44.2%) or a non-classifiable ACS (2.7% vs 7.7%), compared to those without SMurFS. In patients with and without SMuRFs, there were no significant differences in Killip I class (95.4% vs 98%, p=0.370)and GRACE risk score (105 vs 103, p=0.694). Patients with SMuRFS compared to those without had a higher systolic blood pressure (141 mmHg vs 131 mmHg, p=0,03) and a lower glomerular filtration rate (81.8 ml/min/m2 vs 94 ml/min/m2, p=0.04). There were no differences in those with and without SMuRFs in performance of angiography (83% vs 90%, p=0.160), but SMurF-less patients had lower proportion of multivessel disease (18.6% vs 38.2%, p=0.011), higher tendency to percutaneous angioplasty (70.6% vs 57.8%, p=0.073) or performance of CABG (6.1% vs 1.1%, p=0.028).At 5-year follow up (IQR 3-7),SMuRF-less patients had a lower mortality (11.5% vs 23.4%, p=0.049).On multivariable Cox Regression age, chronic renal failure, glomerular filtration rate and GRACE score were independent predictors of death. Coronary angioplasty was a strong protective risk factor of death.However, being SMuRF-less was not protective against mortality. Conclusion: The absence of SMuRFs was not an independent predictor of mortality. Our study highlights the importance of the often-overlooked subgroup of ACS patients with atherosclerosis not predicted by SMuRFs.