Delays in Symptom Recognition May Lead to Worse MI Outcomes

Patient delays in recognizing myocardial infarction symptoms and seeking treatment were found to be associated with increased heart damage, according to a study published Dec. 28in JACC: Cardiovascular Interventions.

ACC/American Heart Association guidelines state that hospitals treating ST segment elevation myocardial infarction (STEMI) patients with emergency percutaneous coronary intervention should do so within 90 minutes or less of reaching the hospital, and the ACC launched the Door-to-Balloon (D2B) Alliance in 2006 to reduce the time to which STEMI patients receive percutaneous coronary intervention in U.S. hospitals.

Researchers reviewed the records of 2,056 patients in the HORIZONS-AMI trial comparing patients with symptom onset-to-balloon time in three categories: 1) two hours and less, 2) more than two hours to four hours, and 3) more than four hours. Results showed that patients in the study who took a total of two to four hours or longer from the onset of symptoms to get treated with a balloon angioplasty to restore blood flow to the heart were less likely to have blood flow fully restored to the heart and were more likely to die within three years than patients treated more quickly.

“The decrease in median door-to-balloon time in recent years has not resulted in a reduction in mortality in STEMI patients,” said Roxana Mehran, MD, FACC, one of the study authors. “This study highlights the need to reconsider the role of door-to-balloon as a performance metric and examine the utility of a broader metric of systems delay such as first medical contact to balloon time as well as total ischemic time.”

In an accompanying editorial, Michael A. Kutcher, MD, FACC, said the door-to-balloon metric and systems in place are extremely valuable and should continue; however, physicians need to pay attention to associated metrics such as the symptoms and signs of the onset of ischemia. He attributed the lack of significant improvement in mortality and morbidity with reduced door-to-balloon time to the fact that microvascular damage can still occur with shorter door to balloon times and can lead to increased risk of death.

“Patients with prolonged symptom onset-to-balloon time are a high-risk group and should be treated accordingly with assertive strategies,” Kutcher continued. “We as an interventional cardiology community should continue to educate the public and health care providers regarding the importance to quantify symptom onset-to-balloon time and follow through with prompt action.”

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: American Heart Association, Angioplasty, Balloon, Angioplasty, Balloon, Coronary, Myocardial Infarction, Percutaneous Coronary Intervention

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