Clinical characteristics, management, and 5-year survival compared between no standard modifiable risk factor (SMuRFless) and ≥ 1 SMuRF ACS cases: an analysis of 15,051 cases from Pakistan

BACKGROUND

There has been an increase in Acute Coronary Syndrome (ACS) patients without standard modifiable risk factors i.e. hypertension, diabetes, dyslipidemia, and tobacco use (SMuRFless) compared to the patients with ≥ 1 SMuRF but this has not been studied in South Asia despite them being a high-risk population. We conducted a comparative analysis of first episodes of ACS cases admitted to a tertiary cardiac center in Pakistan between SMuRFless and ≥ 1 SMuRF patients for clinical presentation, management, in-hospital, and 5-year mortality.

METHODS

We undertook a retrospective study and data of 15,051 patients admitted at Tabba Heart Institute (THI) with the first episode of ACS was extracted from Chest Pain-MI™, and the CathPCI Registry® registry affiliated with the National Cardiovascular Data Registry (NCDR®), USA. Logistic regression and Cox proportional algorithm yielded odds ratio (OR) and hazard ratios (HR) with 95% confidence interval (CI) for associated factors of in-patient and 5-year mortality.

RESULTS

There were 15% SMuRFless cases and in-hospital mortality was 4.1% in SMuRFless vs. 3.9% in the ≥ 1 SMuRF group (p-0.59), the difference remained insignificant after adjusting for age, gender, Killip class, multivessel disease, type of ACS, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) (Adjusted OR:1.1 [0.8, 1.3]. Unadjusted 5-year mortality was 40% lower in the SMuRFless group but the difference was insignificant after adjusting for age, gender, disease at presentation, its severity, and management (Adjusted HR 0.7 95% CI[0.5, 1.0]). STEMI, NSTEMI, Killip class, and multivessel disease increased the risk of overall 5-year mortality.

CONCLUSION

In-hospital and 5-year mortality was not different between the SMuRFless and ≥ 1 SMuRF group, there is a need to understand mediators of immediate and long-term mortality risk in SMuRFless patients.

Association of clinical, laboratory and imaging biomarkers with the occurrence of acute myocardial infarction in patients without standard modifiable risk factors - rationale and design of the "Beyond-SMuRFs Study"

BACKGROUND

Acute myocardial infarction (AMI) remains the leading cause of mortality worldwide. The majority of patients who suffer an AMI have a history of at least one of the standard modifiable risk factors (SMuRFs): smoking, hypertension, dyslipidemia, and diabetes mellitus. However, emerging scientific evidence recognizes a clinically significant and increasing proportion of patients presenting with AMI without any SMuRF (SMuRF-less patients). To date, there are no adequate data to define specific risk factors or biomarkers associated with the development of AMIs in these patients.

METHODS

The ''Beyond-SMuRFs Study'' is a prospective, non-interventional cohort trial designed to enroll patients with AMI and no previous coronary intervention history, who undergo coronary angiography in two academic hospitals in Thessaloniki, Greece. The rationale of the study is to investigate potential relations between SMuRF-less AMIs and the clinical, laboratory and imaging profile of patients, by comparing parameters between patients with and without SMuRFs. Complete demographic and comprehensive clinical data will be recorded, Venous blood samples will be collected before coronary angiography and the following parameters will be measured: total blood count, standard biochemistry parameters, coagulation tests, hormone levels, glycosylated hemoglobin, N- terminal pro-B-type natriuretic peptide and high-sensitivity troponin T levels- as well as serum levels of novel atherosclerosis indicators and pro-inflammatory biomarkers. Furthermore, all participants will undergo a complete and comprehensive transthoracic echocardiographic assessment according to a pre-specified protocol within 24 h from admission. Among others, 2D-speckle-tracking echocardiographic analysis of cardiac chambers and non-invasive calculation of myocardial work indices for the left ventricle will be performed. Moreover, all patients will be assessed for angiographic parameters and the complexity of coronary artery disease using the SYNTAX score. Multivariable linear and logistic regression models will be used to phenotypically characterize SMuRF-less patients and investigate independent clinical, laboratory, echocardiographic and angiographic biomarkers-predictors of SMuRF-less status in AMI.The first patient was enrolled in March 2022 and completion of enrollment is expected until December 2023.

DISCUSSION

The ''Beyond-SmuRFs'' study is an ongoing prospective trial aiming to investigate potential clinical, laboratory and imaging biomarkers associated with the occurrence of AMIs in SMuRF-less patients. The configuration of these patients' profiles could lead to the development of personalized risk-stratification models predicting the occurrence of cardiovascular events in SΜuRF-less individuals.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05535582 / September 10, 2022.

Progression of coronary atherosclerosis in patients without standard modifiable risk factors

Background and aims

The outcome of patients with clinical coronary artery disease despite traditional risk factors is poorly understood.

Methods

Clinical characteristics and plaque burden on serial intravascular ultrasonography were compared in patients without (n ​= ​165) and with (n ​= ​492) standard modifiable risk factors after matching on age, sex and use of statins from a database of 5823 patients participating in clinical trials of anti-atherosclerotic therapies.

Results

Patients without standard modifiable risk factors had lower baseline systolic blood pressure (118 ​± ​12 vs. 129 ​± ​17 ​mmHg, p ​< ​0.001), low-density lipoprotein cholesterol (87 ​± ​21 vs. 104 ​± ​34 ​mg/dl, p ​< ​0.001), triglycerides [106 vs. 136 ​mg/dl, p ​< ​0.001)] and C-reactive protein [1.5 vs. 2.1 ​mg/l, p ​= ​0.001]. At baseline, patients without modifiable risk factors had a lower percent atheroma volume (35.7 ​± ​8.6 vs. 38 ​± ​8.8%, p ​= ​0.004) and total atheroma volume (174.7 ​± ​80 vs. 190.9 ​± ​84 ​mm³, p ​= ​0.03) and less images with calcification (22.2 vs. 26.5%, p ​= ​0.025). The use of aspirin and statin prior to and during the trials was similar. The use of ACE inhibitors and beta blockers was lower in the no risk factor group prior to and during the trials. The change in percent atheroma volume (−0.2 ​± ​2.8 vs. −0.1 ​± ​3.6%, p ​= ​0.71), total atheroma volume (−5.5 ​± ​23.4 vs. −3.8 ​± ​22.7 ​mm³, p ​= ​0.42), and the percentage of patients demonstrating any degree of progression (50.9% vs 45.1%, p ​= ​0.20) were similar in those without and with standard modifiable risk factors, respectively.

Conclusion

Patients who develop clinical coronary atherosclerosis without standard modifiable risk factors have similar rates of plaque progression to those with traditional risk factors.

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Outcome of patients with CAD despite no traditional risk factors is poorly understood.

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Serial intravascular ultrasound studies provide an opportunity to examine this.

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Patients without standard risk factors had lower plaque burden and calcification.

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Use of aspirin and statin was similar in patients with and without standard risk factors.

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Plaque progression was similar in those without and with standard risk factors.