Longer treatment times found for heart attack patients with history of bypass graft surgery

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A study published in JACC: Cardiovascular Interventions has shown that heart attack patients who have previously had coronary artery bypass graft surgery were less likely than other heart attack patients—including those with prior angioplasty—to be treated within the 90-minute recommended “door-to-balloon” time.

Researchers evaluated the records of 15,628 heart attack patients who were treated at 297 US hospitals between June 2009 and September 2011. This data was sourced from the National Cardiovascular Data Registry CathPCI Registry, linked with the ACTION Registry-GWTG. Within this population, 6% of patients had a history of previous coronary artery bypass graft surgery, 19% had previous angioplasty, and 75% had no prior history of procedures.

Heart attack patients with prior revascularisation through surgery were older, with an average age of 66, than those with prior angioplasty, average age 60, or without any previous interventions, average age 59; and they were more likely to have comorbidities, including high blood pressure, high cholesterol, and diabetes.

Results showed that 76% of patients with prior revascularisation via open heart surgery were treated within the recommended 90-minute door-to-balloon time compared to 88.5% of patients with prior angioplasty and 88% of patients with no previous interventions. Door-to-balloon time was achieved in 90% of patients with a prior history of angioplasty with a stent when the new lesion was located in the previous stent and in 87.3% of patients if the lesion was in a non-stented area. For patients with a prior history of bypass graft surgery, 75.9% had their angioplasty done within 90 minutes when the new lesion was in the graft site, as did 77% when the lesion was located in a new vessel.

Overall, 88.3% of patients in the prior surgery group had successful procedures compared with 93.4% of patients who had a prior angioplasty and 94.4% of patients with no prior interventions. After adjusting for clinical and procedural differences, the study found no significant differences in in-hospital mortality, major adverse events, and major bleeding among the three groups.    

Luis Gruberg, the study’s lead author and professor of medicine at Stony Brook University in New York says that patients with a history of prior coronary artery bypass surgery have more complex anatomy and more comorbidities, and therefore have a more prolonged door-to-balloon time compared to the other groups in the study. “Nonetheless, every effort should be made to improve timeliness in patients with a history of previous coronary artery bypass surgery,” Gruberg says.

In an accompanying editorial, John S Douglas, professor of medicine at the Emory University School of Medicine in Atlanta, says the delay in door-to-balloon time for prior bypass graft patients has important implications for salvaging the heart muscle. According to Douglas, because door-to-catheterisation lab and catheterisation lab-to-balloon times were not provided, it’s not clear where the delay occurred. “Increased awareness of ‘time is muscle,’” Douglas says, “may lead to shortened door-to-cath lab times and timely performance” for the more difficult patients.    

Douglas says the study “should be interpreted as a ‘call to action’ with the goal of earliest possible treatment in all heart attack patients, including those who have had prior coronary artery bypass graft surgery.”