16 Nov Acute Coronary Syndrome: How Do Patients Without Critical Stenosis Do?
MedicalResearch.com: What are the main findings of the study?
Dr. Ohlow: This paper reports the finding of a retrospective study including 4.311 consecutive patients with suspected acute coronary syndrome (ACS). Out of them 272 patients with acute onset of chest pain and elevated levels of cardiac necrosis markers did not have significant (≥50% diameter stenosis) coronary artery stenosis on coronary angiography. Aim of this study was to provide further information and understanding of the clinical characteristics and outcome of patients with acute coronary syndrome without critical stenosis, and comparing those with a consecutive series of patients with ACS requiring percutaneous coronary intervention (non-ST-elevation myocardial infarction patients).
Patients presenting without significant coronary stenosis, but with chest pain and elevated troponin level were younger, had less severe angina symptoms, were more likely to be women, had lower level of myocardial necrosis markers (troponin and creatine kinase), and had higher left ventricular ejection fraction compared to patients undergoing angioplasty due to significant coronary obstruction.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Ohlow: The term false-positive has been used to describe the situation in which acute onset of chest pain is associated with an elevated troponin level, but no significant coronary disease is found at coronary angiography. As expected, the prognosis of patients with acute coronary syndrome undergoing angioplasty due to significant coronary artery stenosis is worse than in patients with troponin-positive chest pain and absence significant obstruction (hazard ratio 2.44). However, a significant event-rate of 28.8% over a period of 86 months was found in patients with troponin-positive chest pain and absence significant coronary obstruction. This translates in an annual event-rate of 4%, which is higher than the 2.4% of a healthy population of comparable age. Taking this into account, troponin-positive ACS without relevant coronary artery stenosis does not seem to be a benign condition and may warrant a more aggressive medical therapy in such patients. Interestingly, higher levels of cardiac troponin (more than 1.9 ng/ml at admission) are associated with a worse prognosis in patients with troponin-positive chest pain and absence significant coronary obstruction.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Ohlow: Approximately 6% of all patients admitted for acute onset of chest pain and elevated markers of myocardial necrosis do not show significant (≥50%) coronary stenosis at angiography. The use of several different clinical variables did not help to differentiate patients with and without significant coronary stenosis. The composite outcome (cardiac death, re-infarction and re-hospitalization) of patients undergoing angioplasty due to coronary artery disease is worse than that of patients without significant coronary stenosis and inversely related to troponin levels.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Ohlow: As troponin-positive ACS without relevant coronary artery stenosis does not seem to be a benign condition it would be interesting to evaluate, which type of long term treatment might be the best option for such patients. Whether a treatment similar to acute coronary syndrome with relevant coronary artery stenosis (e.g. dual platelet inhibition for 12 months, and statin medication) can significantly reduce adverse events during follow-up needs to be prospectively investigated in further studies.