Clinical Outcomes in Patients With ST-Segment Elevation MI and No Standard Modifiable Cardiovascular Risk Factors

No standard modifiable cardiovascular risk factors in acute myocardial infarction: prevalence, pathophysiology, and prognosis

Standard modifiable cardiovascular risk factors (SMuRFs), such as hypertension, diabetes, dyslipidemia, and current smoking, are associated with the development of atherosclerotic cardiovascular diseases including acute myocardial infarction (MI). Thus, therapeutic approaches against SMuRFs are important as primary and secondary prevention of cardiovascular diseases. In patients with acute MI, however, the prognosis is counterintuitively poor when SMuRFs are lacking. The growing evidence has explored the prevalence, pathophysiology, and prognosis of SMuRF-less patients in acute MI and suggested the potential underlying mechanisms. This review article summarizes the clinical evidence and relevance of the lack of SMuRFs in acute MI.

Clinical outcomes and coronary artery lesion characteristics of young patients with ST elevation myocardial infarction and no standard modifiable risk factors

BACKGROUND

Among ST-elevation myocardial infarction (STEMI) patients, those with no standard modifiable risk factors (SMuRFs: hypertension, diabetes mellitus, hypercholesterolemia, and smoking) have higher 30-day mortality than those with SMuRFs. Differences in coronary lesion characteristics remain unclear.

METHODS

Data from STEMI patients aged ≤60 years from the Asia Pacific Evaluation of Cardiovascular Therapies Network (Australia, Hong Kong, Malaysia, Singapore, and Vietnam) was retrospectively analysed. Exclusion criteria included incomplete SMuRF data, prior myocardial infarction, or prior coronary revascularisation. Lesion type was defined using the American College of Cardiology criteria. Major adverse cardiovascular events (MACE) were defined as peri-procedural myocardial infarction, emergency coronary artery bypass surgery, cerebrovascular event, or mortality. Multiple logistic regressions were used.

RESULTS

Of 4404 patients, 767 (17.4%) were SMuRFless. SMuRFless patients were more frequently younger (median age 51 vs. 53 years; p < 0.001), female (22.6% vs. 15.5%; p < 0.001), thrombolysed (20.1% vs. 12.5%; p < 0.001), and in cardiogenic shock (11.2% vs. 8.6%; p = 0.020). SMuRFless patients had significantly higher in-hospital MACE (7.2% vs. 4.3%; adjusted odds ratio [aOR] 2.25; 95% confidence interval [CI] 1.24-4.08; p = 0.008) but 1-year mortality was not significantly different (3.6% vs. 5.7%, aOR 0.58; 95% CI 0.06-6.12; p = 0.549). Compared with patients with SMuRFs (4918 lesions), the SMuRFless (940 lesions) had fewer type B2/C lesions (60.8% vs. 65.6%; p = 0.020) and fewer lesions ≥20 mm (51.1% vs. 57.1%; p = 0.002) but more procedural complications (5.1% vs. 2.7%; p < 0.001).

CONCLUSIONS

Among young STEMI patients, the SMuRFless have shorter and less complex lesions, but worse procedural and short-term MACE outcomes.

Characteristics and in-hospital outcomes of female patients presenting with ST-segment-elevation myocardial infarction without standard modifiable cardiovascular risk factors

BACKGROUND

Standard Modifiable Cardiovascular Risk Factors (SMuRF) such as hypertension, diabetes mellitus, hyperlipidemia, and smoking have long been established in the etiology of atherosclerotic disease. We evaluate in-hospital outcomes of female STEMI patients without these risk factors.

METHODS

The National Inpatient Sample databases (2016 to 2021) were queried to identify STEMI admissions as a principal diagnosis using ICD 10 codes. Patients with a history of coronary artery disease, myocardial infarction, coronary bypass graft, percutaneous coronary intervention, takotsubo cardiomyopathy, cocaine abuse, and spontaneous coronary dissection and males were excluded from our study population. A final study population aged >18 years was divided into cohorts of SMuRF and SMuRF-less based on the presence of ≥1 risk factor. Multivariate logistic regression model adjusting for baseline characteristics and comorbidities. The primary outcome was in-hospital mortality. The secondary outcomes are STEMI-related complications and the use of mechanical circulatory support devices.

RESULTS

200,980 patients were identified. 187,776 (93.4 %) patients were identified as having ≥1 SMuRF, and 13,205 (6.6 %) patients were SMuRF-less. Compared to SMuRF patients, SMuRF-less patients are more likely to be white (75.6 % vs. 73.1 %, p < 0.01) and older median age (69 years [IQR: 58-78] vs 67 years [IQR: 57-81], p < 0.01). In comparing co-morbidities, SMuRF-less patients were less likely to have heart failure (28.0 % vs. 23.4 %, p < 0.01), atrial fibrillation/flutter (16.1 % vs. 14.6 %, p = 0.03), chronic pulmonary disease (18.9 % vs. 9.5 %, p < 0.01), obesity (20.7 % vs. 9.2 %, p < 0.01) and aortic disease (1.1 % vs. 0.6 %, p < 0.01). They were however more likely to have dementia (6.9 % vs. 5.7 %, p < 0.01). In evaluating outcomes, SMuRF-less patients had higher in-hospital mortality (aOR 3.2 [95 % CI, 2.9-3.6]; p < 0.01), acute heart failure (aOR 1.6 [95 % CI, 1.4-1.8]; p < 0.01), acute kidney injury (aOR 1.8 [95 % CI, 1.7-2.1]; p < 0.01), and Intra-aortic balloon pump (aOR 1.7 [95 % CI, 1.5-1.9]; p < 0.01). Predictors of higher mortality in SMuRF-less patients include chronic liver disease (OR 6.8, CI 2.4-19.4, p < 0.01), and Hispanic race (OR 1.62, CI 1.1-2.5, p < 0.01). We also found that SMuRF-less patients were less likely to undergo coronary angiography (aOR 0.5 [95 % CI, 0.4-0.5]; p < 0.01) and percutaneous coronary intervention (aOR 0.7 [95 % CI, 0.6-0.8]; p < 0.01).

CONCLUSION

Female SMuRF-less patients presenting with STEMI have worse in-hospital outcomes when compared to patients with ≥1SMuRF.

Chronic coronary syndromes without standard modifiable cardiovascular risk factors and outcomes: the CLARIFY registry

BACKGROUND AND AIMS

It has been reported that patients without standard modifiable cardiovascular (CV) risk factors (SMuRFs-diabetes, dyslipidaemia, hypertension, and smoking) presenting with first myocardial infarction (MI), especially women, have a higher in-hospital mortality than patients with risk factors, and possibly a lower long-term risk provided they survive the post-infarct period. This study aims to explore the long-term outcomes of SMuRF-less patients with stable coronary artery disease (CAD).

METHODS

CLARIFY is an observational cohort of 32 703 outpatients with stable CAD enrolled between 2009 and 2010 in 45 countries. The baseline characteristics and clinical outcomes of patients with and without SMuRFs were compared. The primary outcome was a composite of 5-year CV death or non-fatal MI. Secondary outcomes were 5-year all-cause mortality and major adverse cardiovascular events (MACE-CV death, non-fatal MI, or non-fatal stroke).

RESULTS

Among 22 132 patients with complete risk factor and outcome information, 977 (4.4%) were SMuRF-less. Age, sex, and time since CAD diagnosis were similar across groups. SMuRF-less patients had a lower 5-year rate of CV death or non-fatal MI (5.43% [95% CI 4.08-7.19] vs. 7.68% [95% CI 7.30-8.08], P = 0.012), all-cause mortality, and MACE. Similar results were found after adjustments. Clinical event rates increased steadily with the number of SMuRFs. The benefit of SMuRF-less status was particularly pronounced in women.

CONCLUSIONS

SMuRF-less patients with stable CAD have a substantial but significantly lower 5-year rate of CV death or non-fatal MI than patients with risk factors. The risk of CV outcomes increases steadily with the number of risk factors.

Prevalence and outcomes of patients with SMuRF-less acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND

There is increasing awareness that patients without standard modifiable risk factors (SMuRFs; diabetes, hypercholesterolaemia, hypertension and smoking) may represent a unique subset of patients with acute coronary syndrome (ACS). We aimed to investigate the prevalence and outcomes of patients with SMuRF-less ACS undergoing percutaneous coronary intervention (PCI) compared with those with SMuRFs.

METHODS

We analysed data from the Melbourne Interventional Group PCI Registry. Patients with coronary artery disease were excluded. The primary outcome was 30-day mortality. Secondary outcomes included in-hospital and 30-day events. Long-term mortality was investigated using Cox-proportional hazards regression.

RESULTS

From 1 January 2005 to 31 December 2020, 2727/18 988 (14.4%) patients were SMuRF less, with the proportion increasing over time. Mean age was similar for patients with and without SMuRFs (63 years), and fewer females were SMuRF-less (19.8% vs 25.4%, p<0.001). SMuRF-less patients were more likely to present with cardiac arrest (6.6% vs 3.9%, p<0.001) and ST-elevation myocardial infarction (59.1% vs 50.8%, p<0.001) and were more likely to experience postprocedural cardiogenic shock (4.5% vs 3.6%, p=0.019) and arrhythmia (11.2% vs 9.9%, p=0.029). At 30 days, mortality, myocardial infarction, revascularisation and major adverse cardiac and cerebrovascular events did not differ between the groups. During median follow-up of 7 years, SMuRF-less patients had an adjusted 13% decreased rate of mortality (HR 0.87 (95% CI 0.78 to 0.97)).

CONCLUSIONS

The proportion of SMuRF-less patients increased over time. Presentation was more often a devastating cardiac event compared with those with SMuRFs. No difference in 30-day outcomes was observed and SMuRF-less patients had lower hazard for long-term mortality.

Association of Lipoprotein (a) and Standard Modifiable Cardiovascular Risk Factors With Incident Myocardial Infarction: The Mass General Brigham Lp(a) Registry

BACKGROUND

Lipoprotein (a) [Lp(a)] is a robust predictor of coronary heart disease outcomes, with targeted therapies currently under investigation. We aimed to evaluate the association of high Lp(a) with standard modifiable risk factors (SMuRFs) for incident first acute myocardial infarction (AMI).

METHODS AND RESULTS

This retrospective study used the Mass General Brigham Lp(a) Registry, which included patients aged ≥18 years with an Lp(a) measurement between 2000 and 2019. Exclusion criteria were severe kidney dysfunction, malignant neoplasm, and prior known atherosclerotic cardiovascular disease. Diabetes, dyslipidemia, hypertension, and smoking were considered SMuRFs. High Lp(a) was defined as >90th percentile, and low Lp(a) was defined as <50th percentile. The primary outcome was fatal or nonfatal AMI. A combination of natural language processing algorithms, International Classification of Diseases (ICD) codes, and laboratory data was used to identify the outcome and covariates. A total of 6238 patients met the eligibility criteria. The median age was 54 (interquartile range, 43-65) years, and 45% were women. Overall, 23.7% had no SMuRFs, and 17.8% had ≥3 SMuRFs. Over a median follow-up of 8.8 (interquartile range, 4.2-12.8) years, the incidence of AMI increased gradually, with higher number of SMuRFs among patients with high (log-rank P=0.031) and low Lp(a) (log-rank P<0.001). Across all SMuRF subgroups, the incidence of AMI was significantly higher for patients with high Lp(a) versus low Lp(a). The risk of high Lp(a) was similar to having 2 SMuRFs. Following adjustment for confounders and number of SMuRFs, high Lp(a) remained significantly associated with the primary outcome (hazard ratio, 2.9 [95% CI, 2.0-4.3]; P<0.001).

CONCLUSIONS

Among patients with no prior atherosclerotic cardiovascular disease, high Lp(a) is associated with significantly higher risk for first AMI regardless of the number of SMuRFs.

Impact of the number of modifiable risk factors on clinical outcomes after percutaneous coronary intervention: An analysis from the e-Ultimaster registry

Aims

A substantial proportion of the patients undergoing percutaneous coronary intervention (PCI) have none of the of standard modifiable cardiovascular risk factors (SMuRFs): hypertension, diabetes, hypercholesterolaemia and smoking. The aim of this analysis was to compare clinical outcomes after PCI according to the number of SMuRFs.

Methods

Patients with an indication for a PCI were stratified based upon the number of SMuRFs: 0, 1, 2 or 3-4. The primary outcome was target lesion failure (TLF), a composite of cardiac death, target vessel-related myocardial infarction or clinically driven target lesion revascularization at 1-year. Inverse weighted propensity score (IWPS) adjustment was performed to adjust for differences in baseline characteristics.

Results

The prevalence of SMuRFs was: 0 SMuRF 16.4 %; 1 SMuRF 27.8 %; 2 SMuRFs 34.7 % and 3-4 SMuRFs 21.1 %. Patients without SMuRFs were younger, more likely to be male and had less complex coronary artery disease. The incidence of TLF increased with the number of SMuRFs: 2.65 %, 2.75 %, 3.23 %, and 4.24 %, Ptrend < 0.001. The relative risk (RR) for a TLF was 60 % higher (95 % confidence interval 1.32-1.93, p < 0.01) for patients with 3-4 SMuRFs compared to patients without SMuRFs. The trend remained (Ptrend < 0.01) after IWPS with TLF rates of 2.88 %, 2.64 %, 2.88 % and 3.65 %. The RR for a TLF was 27 % higher (95 % CI 1.05-1.53, p < 0.01).

Conclusion

The incidence of clinical events at 1-year increased with the number of SMuRFs. While patients without SMuRFs have a relatively favourable risk profile, more research is needed to optimize therapeutic management in the majority of patients.

Infarct severity and outcomes in ST-elevation myocardial infarction patients without standard modifiable risk factors - A multicenter cardiac magnetic resonance study

BACKGROUND

Standard modifiable cardiovascular risk factors (SMuRFs) are well-established players in the pathogenesis of ST-elevation myocardial infarction (STEMI). However, in a significant proportion of STEMI patients, no SMuRFs can be identified, and the outcomes of this subgroup are not well described.

OBJECTIVES

To assess the infarct characteristics at myocardial-tissue level and subsequent clinical outcomes in SMuRF-less STEMIs.

METHODS

This multicenter, individual patient-data analysis included 2012 STEMI patients enrolled in four cardiac magnetic resonance (CMR) imaging studies conducted in Austria, Germany, Scotland, and the Netherlands. Unstable patients at time of CMR (e.g. cardiogenic shock/after cardiac arrest) were excluded. SMuRF-less was defined as absence of hypertension, smoking, hypercholesterolemia, and diabetes mellitus. All patients underwent CMR 3(interquartile range [IQR]:2-4) days after infarction to assess left ventricular (LV) volumes and ejection fraction, infarct size and microvascular obstruction (MVO). Clinical endpoints were defined as major adverse cardiovascular events (MACE), including all-cause mortality, re-infarction and heart failure.

RESULTS

No SMuRF was identified in 185 patients (9%). These SMuRF-less patients were older, more often male, had lower TIMI risk score and pre-interventional TIMI flow, and less frequently multivessel-disease. SMuRF-less patients did not show significant differences in CMR markers compared to patients with SMuRFs (all p > 0.10). During a median follow-up of 12 (IQR:12-27) months, 199 patients (10%) experienced a MACE. No significant difference in MACE rates was observed between SMuRF-less patients and patients with SMuRFs (8vs.10%, p = 0.39).

CONCLUSIONS

In this large individual patient-data pooled analysis of low-risk STEMI patients, infarct characteristics and clinical outcomes were not different according to SMuRF status.

In-hospital and 1-year outcomes of patients without modifiable risk factors presenting with acute coronary syndrome undergoing PCI: a Sex-stratified analysis

Aim

A considerable proportion of patients admitted with acute coronary syndrome (ACS) have no standard modifiable cardiovascular risk factors (SMuRFs: hypertension, diabetes mellitus, dyslipidemia, and cigarette smoking). The outcomes of this population following percutaneous coronary intervention (PCI) are debated. Further, sex differences within this population have yet to be established.

Methods

This retrospective cohort study included 7,847 patients with ACS who underwent PCI. The study outcomes were in-hospital mortality, all-cause mortality, and major adverse cardio-cerebrovascular events (MACCE). The association between the absence of SMuRFs (SMuRF-less status) and outcomes among all the patients and each sex was assessed using logistic and Cox proportional hazard regressions.

Results

Approximately 11% of the study population had none of the SMuRFs. During 12.13 [11.99-12.36] months of follow-up, in-hospital mortality (adjusted-odds ratio (OR):1.51, 95%confidence interval (CI): 0.91-2.65, P:0.108), all-cause mortality [adjusted-hazard ratio (HR): 1.01, 95%CI: 0.88-1.46, P: 0.731], and MACCE (adjusted-HR: 0.93, 95%CI:0.81-1.12, P: 0.412) did not differ between patients with and without SMuRFs. Sex-stratified analyses recapitulated similar outcomes between SMuRF+ and SMuRF-less men. In contrast, SMuRF-less women had significantly higher in-hospital (adjusted-OR: 3.28, 95%CI: 1.92-6.21, P < 0.001) and all-cause mortality (adjusted-HR:1.41, 95%CI: 1.02-3.21, P: 0.008) than SMuRF+ women.

Conclusions

Almost one in 10 patients with ACS who underwent PCI had no SMuRFs. The absence of SMuRFs did not confer any benefit in terms of in-hospital mortality, one-year mortality, and MACCE. Even worse, SMuRF-less women paradoxically had an excessive risk of in-hospital and one-year mortality.

Characteristics and Outcomes of Young Patients With ST-Elevation Myocardial Infarction Without Standard Modifiable Risk Factors

Patients with ST-elevation myocardial infarction (STEMI) with no standard modifiable risk factors (SMuRFs: hypertension, diabetes mellitus, hypercholesterolemia, and smoking) have worse short-term mortality than those with SMuRFs. Whether this association extends to younger patients is unclear. A retrospective cohort study was performed of patients aged 18 to 45 years with STEMI at 3 Australian hospitals between 2010 and 2020. Nonatherosclerotic causes of STEMI were excluded. The primary outcome was 30-day all-cause mortality. Secondary outcomes included 1 and 2-year mortality. Cox proportional hazards analysis was used. Of 597 patients, the median age was 42 (interquartile range 38 to 44) years, 85.1% were men and 8.4% were SMuRF-less. Patients who are SMuRF-less were >2 times more likely to have cardiac arrest (28.0% vs 12.6%, p = 0.003); require vasopressors (16.0% vs 6.8%, p = 0.018), mechanical support (10.0% vs 2.3%, p = 0.046), or intensive care admission (20.0% vs 5.7%, p <0.001); and have higher rate of left anterior descending artery infarcts than those with SMuRFs (62.0% vs 47.2%, p = 0.045). No significant differences in thrombolysis or percutaneous intervention were observed. Guideline-directed medical therapy at discharge was high (>90%), and not different in the SMuRF-less. 30-day mortality was almost fivefold higher in the SMuRF-less (hazard ratio 4.70, 95% confidence interval 1.66 to 13.35, p = 0.004), remaining significant at 1 and 2 years. In conclusion, young patients who are SMuRF-less have a higher 30-day mortality after STEMI than their counterparts with SMuRFs. This may be partially mediated by higher rates of cardiac arrest and left anterior descending artery territory events. These findings further highlight the need for improved prevention and management of SMuRF-less STEMI.

Impact of myocardial deformation on risk prediction in patients following acute myocardial infarction

Background

Strain analyses derived from cardiovascular magnetic resonance-feature tracking (CMR-FT) provide incremental prognostic benefit in patients sufferring from acute myocardial infarction (AMI). This study aims to evaluate and revalidate previously reported prognostic implications of comprehensive strain analyses in a large independent cohort of patients with ST-elevation myocardial infarction (STEMI).

Methods

Overall, 566 STEMI patients enrolled in the CONDITIONING-LIPSIA trial including pre- and/or postconditioning treatment in addition to conventional percutaneous coronary intervention underwent CMR imaging in median 3 days after primary percutaneous coronary intervention. CMR-based left atrial (LA) reservoir (Es), conduit (Ee), and boosterpump (Ea) strain analyses, as well as left ventricular (LV) global longitudinal strain (GLS), circumferential strain (GCS), and radial strain (GRS) analyses were carried out. Previously identified cutoff values were revalidated for risk stratification. Major adverse cardiac events (MACE) comprising death, reinfarction, and new congestive heart failure were assessed within 12 months after the occurrence of the index event.

Results

Both atrial and ventricular strain values were significantly reduced in patients with MACE (p < 0.01 for all). Predetermined LA and LV strain cutoffs enabled accurate risk assessment. All LA and LV strain values were associated with MACE on univariable regression modeling (p < 0.001 for all), with LA Es emerging as an independent predictor of MACE on multivariable regression modeling (HR 0.92, p = 0.033). Furthermore, LA Es provided an incremental prognostic value above LVEF (a c-index increase from 0.7 to 0.74, p = 0.03).

Conclusion

External validation of CMR-FT-derived LA and LV strain evaluations confirmed the prognostic value of cardiac deformation assessment in STEMI patients. In the present study, LA strain parameters especially enabled further risk stratification and prognostic assessment over and above clinically established risk parameters.

Clinical Trial Registration

ClinicalTrials.gov, identifier NCT02158468.

Characteristics and outcomes of patients with no standard modifiable risk factors undergoing primary revascularization for acute myocardial infarction: Insights from the nationwide Japanese percutaneous coronary intervention registry

BACKGROUND

Identification of and therapeutic approaches to standard modifiable risk factors (SMuRFs), including hypertension, diabetes, dyslipidemia, and smoking, have led to improved survival of patients at risk for coronary events. However, recent studies have indicated that a significant proportion of patients with acute myocardial infarction (AMI) have no SMuRFs. We aimed to assess in-hospital outcomes and the prevalence of these patients using the Japanese nationwide percutaneous coronary intervention (J-PCI) registry.

METHODS

The J-PCI is a procedure-based registration program in Japan. A total of 115,437 PCI procedures were performed on patients with AMI between January 2019 and December 2020. The participants were divided into 2 groups: those with at least 1 SMuRF and those without any SMuRFs. The primary outcome was in-hospital mortality.

RESULTS

Of the 115,437 patients with AMI, 1,777 (1.6%) had no SMuRFs. Patients without SMuRFs were older; more likely to have left main disease; and more likely to present with heart failure, cardiogenic shock, and cardiac arrest than those with SMuRFs, resulting in higher rates of mechanical circulatory support use and impaired post-PCI coronary blood flow. In-hospital mortality was significantly higher in patients without SMuRFs than in those with SMuRFs (18.3% vs 5.3%, P < .001), irrespective of the presence or absence of ST-segment elevation.

CONCLUSIONS

In Japan, where annual health checks are mandated under universal health care coverage, the vast majority of patients with AMI undergoing PCI have SMuRFs. However, although small in number, patients without SMuRFs are more likely to present with life-threatening conditions and have worse in-hospital survival.

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.

Standard modifiable cardiovascular risk factors in patients with acute coronary syndrome: A report from multicenter percutaneous coronary intervention registry

BACKGROUND

High mortality in patients with acute coronary syndrome (ACS) without standard modifiable cardiovascular risk factors [SMuRFs (e.g. diabetes, hypertension, smoking, and dyslipidemia)] has been reported. However, details regarding their acute presentation and reasons for the excess risk remain unclear.

METHOD

Patient-level data were extracted from a multicenter procedure-based registry (KiCS-PCI). We analyzed consecutive patients with ACS who underwent de novo percutaneous coronary intervention (PCI) between 2009 and 2020. The primary outcome of interest was the in-hospital mortality.

RESULTS

Among the 10,523 patients with ACS, 7775 met the inclusion criteria. Patients without SMuRFs who underwent PCI [n = 529 (6.8 %)] were older [median 71 (IQR: 63-79) vs. 68 (59-76) years, p < 0.001] and more often presented with cardiogenic shock or cardiopulmonary arrest (14.6 % vs. 8.6 %, p < 0.001; 12.7 % vs. 5.3 %, p < 0.001, respectively). In patients with ST-elevation myocardial infarction (STEMI), median door-to-balloon time was significantly longer in SMuRF-less patients (90 min vs 82 min). In-hospital death was significantly higher in SMuRF-less patients [10.2 % vs. 4.1 %, p < 0.001, adjusted odds ratio, 1.81 (95%CI, 1.26-2.59); p = 0.001], whereas the rate of procedural complications showed no significant difference. When stratified by the ACS presentation pattern, the findings were consistent, although the association between SMuRF-less and the increased risk of in-hospital mortality was not statistically significant in patients with non-ST-elevation- (NSTE)-ACS.

CONCLUSIONS

SMuRF-less ACS patients frequently presented with cardiopulmonary arrest and/or cardiogenic shock, leading to high in-hospital mortality. When stratified by the ACS presentation pattern, the association of SMuRF-less and the increased risk of mortality was more prominent in STEMI patients and it was not statistically significant in NSTE-ACS patients. Almost half of these patients had amendable left main trunk or left anterior descending artery disease and treating clinicians should be aware of this paradox to avoid the delay in treatment.

Higher mortality in acute coronary syndrome patients without standard modifiable risk factors: Results from a global meta-analysis of 1,285,722 patients

BACKGROUND

Standard modifiable cardiovascular risk factors (SMuRF), comprising diabetes, hyperlipidemia, hypertension, and smoking, are used for risk stratification in acute coronary syndrome (ACS). Recent studies showed an increasing proportion of SMuRF-less ACS patients.

METHODS

Embase, Medline and Pubmed were searched for studies comparing SMuRF-less and SMuRF patients with first presentation of ACS. We conducted single-arm analyses to determine the proportion of SMuRF-less patients in the ACS cohort, and compared the clinical presentation and outcomes of these patients.

RESULTS

Of 1,285,722 patients from 15 studies, 11.56% were SMuRF-less. A total of 7.44% of non-ST-segment-elevation ACS patients and 12.87% of ST-segment-elevation myocardial infarction (STEMI) patients were SMuRF-less. The proportion of SMuRF-less patients presenting with STEMI (60.71%) tended to be higher than those with SMuRFs (49.21%). Despite lower body mass index and fewer comorbidities such as chronic kidney disease, peripheral arterial disease, stroke and heart failure, SMuRF-less patients had increased in-hospital mortality (RR:1.57, 95%CI:1.38 to 1.80) and cardiogenic shock (RR:1.39, 95%CI:1.18 to 1.65), but lower risk of heart failure (RR:0.91, 95%CI:0.83 to 0.99). On discharge, SMuRF-less patients were prescribed less statins (RR:0.93, 95%CI:0.91 to 0.95), beta-blockers (RR:0.94, 95%CI:0.92 to 0.96), P2Y12 inhibitors (RR: 0.98, 95%CI: 0.96 to 0.99), and angiotensin-converting-enzyme inhibitor or angiotensin-receptor blocker (RR:0.92, 95%CI:0.75 to 0.91).

CONCLUSION

In this study level meta-analysis, SMuRF-less ACS patients demonstrate higher mortality compared with patients with at least one traditional atherosclerotic risk factor. Underuse of guideline-directed medical therapy amongst SMuRF-less patients is concerning. Unraveling novel risk factors amongst SMuRF-less individuals is the next important step.

SUMMARY

Standard modifiable cardiovascular risk factors (SMuRF), comprising diabetes mellitus, hyperlipidemia, hypertension, and smoking, are often used for risk stratification in acute coronary syndrome (ACS). Recent studies showed an increasing proportion of SMuRF-less ACS patients. Of 1,285,722 ACS patients, 11.56% were SMuRF-less. Despite lower body mass index and fewer comorbidities, SMuRF-less patients had increased in-hospital mortality and cardiogenic shock. However, despite worse outcomes, SMuRF-less patients were prescribed less guideline-directed medical therapies on discharge.