What is the clinical evidence from this study?

Study design: Cohort. Population: Spontaneous Coronary Artery Dissection (SCAD) (n=26598). Intervention: null vs. Patients without SCAD. Primary outcome: 1-year mortality (HR 0.27, 95% CI 0.14-0.51, p=<0.001).

What does this research mean for the field?

Patients with spontaneous coronary artery dissection (SCAD) have a 1-year mortality rate of 2.4%, significantly lower than the 8.8% mortality rate in patients without SCAD, indicating lower mortality associated with SCAD. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

May 14, 2019Open Access

Characteristics and Clinical Outcomes of Patients With Spontaneous Coronary Artery Dissection

Q: What are the key findings of this study?

Patients with spontaneous coronary artery dissection experienced a 1-year mortality of 2.4%, significantly lower than 8.8% in those without SCAD, indicating lower mortality associated with SCAD.

Q: What does this research mean for the field?

Patients with spontaneous coronary artery dissection (SCAD) have a 1-year mortality rate of 2.4%, significantly lower than the 8.8% mortality rate in patients without SCAD, indicating lower mortality associated with SCAD. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.SUPPORTS_CONSENSUS.

Key Result

Patients with spontaneous coronary artery dissection experienced a 1-year mortality of 2.4%, significantly lower than 8.8% in those without SCAD, indicating lower mortality associated with SCAD.

Study Design

Type

Cohort (n=26,598)

Multicenter

Yes

Structured PICO

Does spontaneous coronary artery dissection (SCAD) have different long-term mortality compared to non-SCAD acute myocardial infarction, and what factors are associated with recurrent SCAD?

Population

26,598 adults (≥18 years) hospitalized with a principal diagnosis of acute myocardial infarction who underwent coronary angiography, including 208 (0.78%) diagnosed with spontaneous coronary artery dissection (SCAD). SCAD patients had a mean age of 49.0 years, 88.9% were women, and the cohort was ethnically diverse (41.4% Hispanic, 15.9% Black).

Intervention

Spontaneous coronary artery dissection (SCAD) as the etiology of acute myocardial infarction.

Comparator

Patients with acute myocardial infarction without SCAD (both the full cohort of 26,390 patients and a 1:1 propensity score-matched cohort of 208 patients matched for age, sex, ethnicity, and comorbidities).

Outcome

Mortality (short-term and long-term) and recurrent SCAD.hard clinical

Patients with SCAD have favorable survival driven primarily by their younger age and fewer comorbidities, but face a persistent long-term risk of recurrence, particularly those with fibromuscular dysplasia or migraines.

Main Result

Effect estimate: HR 0.27 (95% CI 0.14-0.51)

Absolute Event Rate: 2.4% vs 8.8%

p-value: p=<0.001

Limitations

This is a nonrandomized observational study, which may lead to variability in diagnosis and management.
Exclusions of iatrogenic dissections may limit generalizability.
Not all patients underwent systematic screening for associated conditions like fibromuscular dysplasia.

Abstract

Background The goal of this study is to report the characteristics and long‐term clinical outcomes of patients with spontaneous coronary artery dissection (SCAD) and to identify factors associated with recurrent SCAD . Methods and Results This is a retrospective cohort study that included patients who underwent coronary angiography for evaluation of acute myocardial infarction between 2006 and 2016. Among 26 598 patients hospitalized with a principal diagnosis of acute myocardial infarction, 208 (0.78%) were diagnosed with SCAD . Patients with SCAD were younger (49.0±11.6 versus 65.6±12.2 years) and more likely to be women (88.9% versus 31.6%). Atherosclerotic risk factors, such as hypertension, hyperlipidemia, obesity, and diabetes mellitus, were less prevalent. Median follow‐up was 4.7 years. Mortality was lower in patients with SCAD (1‐year mortality: 2.4% versus 8.8%; P <0.001). After using propensity score matching to control for differences in age, sex, and comorbidities, the difference in mortality was no longer present, suggesting that lower mortality in patients with SCAD is attributed primarily to their baseline characteristics. Recurrent SCAD occurred in 22 patients (10.6%). Multivariate Cox regression modeling showed concomitant fibromuscular dysplasia (hazard ratio, 5.1; 95% CI , 1.6–15.8; P =0.005) and migraine headaches (hazard ratio, 3.4; 95% CI , 1.4–8.4; P =0.008) to be associated with increased risk of recurrent SCAD . Conclusions Among patients with acute myocardial infarction, patients with SCAD have a lower risk of mortality, which is attributed primarily to their younger age, female sex, and low prevalence of atherosclerotic risk factors. Risk of recurrent SCAD persists years after the initial presentation. Patients with fibromuscular dysplasia and migraine are at higher risk for recurrent SCAD .