Acute coronary syndrome without critical epicardial coronary disease: prevalence, characteristics, and outcome
Marc-Alexander Ohlow1, Vincent Wong2, Michele Brunelli2
1Cardiology Clinic, Zentralklinik Bad Berka, 99437 Bad Berka, Germany.
Insights
Patients with myocardial infarction (MI) but no significant coronary artery stenosis have a better prognosis. Lower troponin levels in these patients correlate with improved event-free survival and reduced mortality.
Area of Science:
- Cardiology
- Internal Medicine
- Clinical Research
Background:
- Acute chest pain with elevated cardiac markers can occur without significant epicardial coronary artery stenosis.
- This clinical scenario, though occasional, warrants investigation into patient characteristics and outcomes.
Purpose of the Study:
- To retrospectively analyze clinical features and outcomes of myocardial infarction (MI) patients without significant coronary artery stenosis.
- To compare these patients with those undergoing percutaneous coronary intervention for non-ST-elevation MI (NSTEMI).
Main Methods:
- Retrospective analysis of 4311 consecutive MI patients from May 2002 to April 2011.
- Comparison between 272 patients with MI but no significant stenosis (Group I) and 253 NSTEMI patients (Group II).
Main Results:
- Group I patients were younger, more likely female, had less severe angina, lower cardiac biomarker levels (troponin, creatine kinase), and higher left ventricular ejection fraction.
- At a mean follow-up of 22.3 months, Group I showed significantly lower all-cause and cardiac mortality (4.9% vs 14.3% and 2.9% vs 10.1%, respectively).
- Event-free survival was higher in Group I (58.4% vs 28.8%), inversely related to troponin levels.
Conclusions:
- Absence of significant coronary stenosis is a minority cause of MI presentation.
- This condition is associated with a better prognosis compared to NSTEMI.
- Prognosis is inversely related to the initial troponin level.
Background:
Absence of significant epicardial coronary artery stenosis in patients with acute onset of chest pain and elevation of myocardial necrosis markers is occasionally observed. The aim of this study was to retrospectively analyze the clinical characteristics and the outcome of such patients.
Methods:
All patients with myocardial infarction (MI) but without significant coronary artery stenosis (≥50%) on angiography from May 2002 to April 2011 were compared with patients undergoing percutaneous coronary intervention due to non-ST-elevation MI (NSTEMI).
Results:
Of 4311 consecutive patients with MI, 272 patients (6.3%) did not show significant coronary artery stenosis (group I) and were compared with 253 NSTEMI patients (group II). Younger age (61.9±14.0 vs 65.4±12.0 years; P=.003), female sex (49.3% vs 28.9%; P<.001), less severe anginal symptoms (Canadian Cardiovascular Society class III/IV 41.9% vs 49.8%; P=.05), lower level of myocardial necrosis marker (1.9±6.7 vs 27.4±68.7 ng/mL [troponin], 3.3±4 vs 14.2±20 mmol/L [creatine kinase]; P<.001 for both), and higher left ventricular ejection fraction (58.7%±12.6% vs 48.1%±12.4%; P<.01) were associated with group I patients. At a mean follow-up of 22.3±22.9 months, all-cause and cardiac mortality was lower in group I patients (4.9% vs 14.3%; and 2.9% vs 10.1%; P<.01, for both). Event-free survival was more frequent in group I patients (58.4% vs 28.8%; P<.0001) and inversely related to the troponin level.
Conclusions:
Absence of significant coronary stenosis accounts for a minority of patients presenting with MI and is associated with a better outcome compared to patients with NSTEMI, and the prognosis is inversely related to the troponin level.
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