Among diabetes patients with multivessel coronary artery disease (CAD) presenting with non-ST elevation myocardial infarction (NSTEMI), only slightly more than a third get coronary artery bypass grafts (CABG) as recommended by guidelines, a registry study showed.
Between 2008 and 2014, 36.4% of such patients received surgery, while 46.2% got percutaneous coronary intervention (PCI), and 17.3% had no revascularization at all during index admission. PCI actually gained during that period, rising from 45% in the third quarter of 2008 to 48.9% in the fourth quarter of 2014 (P=0.0002 for trend), whereas CABG did not budge in usage (36.1% to 34.7%, P=0.88 for trend).
Although guidelines currently recommend surgery over PCI for these patients, “only one third undergo CABG during the index admission, reported Dharam J. Kumbhani, MD, SM, of UT Southwestern Medical Center in Dallas, and colleagues online in Circulation: Cardiovascular Quality and Outcomes. “Furthermore, the use of PCI, but not CABG, increased modestly over the past 6 years.”
Kumbhani and colleagues added that “there are marked variations in the proportional use of CABG and PCI among participating hospitals, which persist even among angiographic subgroups, a finding that suggests that local practice patterns play an important role in selection of CABG versus PCI in NSTEMI patients with [diabetes] and multivessel CAD.”
Patients were more likely to be directed to CABG instead of PCI if they had:
- Left main or proximal left anterior descending disease (odds ratio [OR] 4.26, 95% confidence interval [CI] 4.01-4.52)
- Signs of heart failure on presentation (OR 1.31, 95% CI 1.20-1.42)
- Left ventricular ejection fraction (LVEF) of 40% to 50% (OR 1.22, 95% CI 1.13-1.31)
- Age 72 years or younger (OR 1.11, 95% CI 1.08-1.13)
- Body mass index of 25 kg/m2 or less (OR 1.06, 95% CI 1.03-1.09)
The study from Kumbhani’s group included 29,769 patients who were voluntarily enrolled in the Acute Coronary Treatment and Intervention Outcomes Network Registry-Get with the Guidelines (ACTION Registry-GWTG).
Factors associated with decisions for PCI over surgery were:
- Female sex (OR 0.76, 95% CI 0.71-0.81)
- LVEF under 25% (OR 0.81, 95% CI 0.69-0.94)
- Medicare versus private insurance (OR 0.87, 95% CI 0.81-0.94)
- Current dialysis (OR 0.75, 95% CI 0.65-0.87)
- History of myocardial infarction (OR 0.86, 95% CI 0.78-0.94)
- History of heart failure (OR 0.71, 95% CI 0.64-0.78)
According to the authors, “the choice of optimal revascularization strategy in this patient population is particularly influenced by the severity of underlying CAD.”
“Among high-risk patients (three-vessel CAD and proximal left anterior descending disease involvement), CABG has been the revascularization strategy of choice throughout the study period. Similarly, PCI is the preferred revascularization strategy among lower-risk patients (two-vessel CAD without proximal left anterior descending disease involvement) with no significant change over time,” they wrote.
Furthermore, they noted, the “hospital-level variation in the proportional use of CABG and PCI across participating centers” possibly reflects “a lack of clinical consensus among physicians regarding the optimal revascularization strategy for these patients, rather than a lack of awareness regarding the evidence base.”
As for why CABG seems to have stalled in general use, “the provider’s preferences may also bias the patients to align toward less invasive option,” Kumbhani’s group argued. “Differences in local expertise of interventional cardiologists and cardiothoracic surgeons and systems of perioperative care could also influence the decision-making process.”
The authors acknowledged that they lacked data on several variables that could have influenced the decision to go with a particular revascularization strategy. For one, there were no angiographic data such as SYNTAX scores and presence of thrombus; and no information on several important comorbidities.
“As a result, real-world complex clinical decision-making could not be elucidated from the database,” they cautioned.
Kumbhani reported receiving research grants and honoraria from the American College of Cardiology.
Various other authors disclosed relationships with industry.
Circulation: Cardiovascular Quality and Outcomes
Pandey A, et al “Revascularization trends in patients with diabetes mellitus and multivessel coronary artery disease presenting with non-ST elevation myocardial infarction: insights from the NCDR ACTION registry-GWTG” Circ Cardiovasc Qual Outcomes 2016; DOI: 10.1161/CIRCOUTCOMES.115.002084.