Original Research
Prognostic Role of CMR and Conventional Risk Factors in Myocardial Infarction With Nonobstructed Coronary Arteries

https://doi.org/10.1016/j.jcmg.2018.12.023Get rights and content
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Abstract

Objectives

This study sought to assess the prognostic impact of cardiac magnetic resonance (CMR) and conventional risk factors in patients with myocardial infarction with nonobstructed coronaries (MINOCA).

Background

Myocardial infarction with nonobstructed coronary arteries (MINOCA) represents a diagnostic dilemma, and the prognostic markers have not been clarified.

Methods

A total of 388 consecutive patients with MINOCA undergoing CMR assessment were identified retrospectively from a registry database and prospectively followed for a primary clinical endpoint of all-cause mortality. A 1.5-T CMR was performed using a comprehensive protocol (cines, T2-weighted, and late gadolinium enhancement sequences). Patients were grouped into 4 categories based on their CMR findings: myocardial infarction (MI) (embolic/spontaneous recanalization), myocarditis, cardiomyopathy, and normal CMR.

Results

CMR (performed at a median of 37 days from presentation) was able to identify the cause for the troponin rise in 74% of the patients (25% myocarditis, 25% MI, and 25% cardiomyopathy), whereas a normal CMR was identified in 26%. Over a median follow-up of 1,262 days (3.5 years), 5.7% patients died. The cardiomyopathy group had the worst prognosis (mortality 15%; log-rank test: 19.9; p < 0.001), MI had 4% mortality, and 2% in both myocarditis and normal CMR. In a multivariable Cox regression model (including clinical and CMR parameters), CMR diagnosis of cardiomyopathy and ST-segment elevation on presentation electrocardiogram (ECG) remained the only 2 significant predictors of mortality. Using presentation with ECG ST-segment elevation and CMR diagnosis of cardiomyopathy as risk markers, the mortality risk rates were 2%, 11%, and 21% for presence of 0, 1, and 2 factors, respectively (p < 0.0001).

Conclusions

In a large cohort of patients with MINOCA, CMR (median 37 days from presentation) identified a final diagnosis in 74% of patients. Cardiomyopathy had the highest mortality, followed by MI. The strongest predictors of mortality were a CMR diagnosis of cardiomyopathy and ST-segment elevation on presentation ECG.

Key Words

ACS unobstructed coronaries
CMR
MINOCA
myocardial infarction myocarditis
Takotsubo cardiomyopathy

Abbreviations and Acronyms

ACS
acute coronary syndrome
CMR
cardiac magnetic resonance
ECG
electrocardiogram
iEDV
indexed end-diastolic volume
LGE
late gadolinium enhancement
LV
left ventricular
LVEF
left ventricular ejection fraction
MI
myocardial infarction
MINOCA
myocardial infarction with nonobstructed coronary artery
NSTE-ACS
non-ST-segment elevation-acute coronary syndrome
RV
right ventricular
RWMA
regional wall motion abnormality
STEMI
ST-segment elevation myocardial infarction
STIR
short tau inversion recovery

Cited by (0)

Dr. Bucciarelli-Ducci is supported by the National Institute of Health Research Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol and is a consultant for Circle Cardiovascular Imaging. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research, or the Department of Health and Social Care. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.