Differential Impact of Diabetes Type on AMI Clinical Outcomes

Patients with diabetes presenting with acute myocardial infarction (AMI) have worse in-hospital clinical outcomes compared with patients without diabetes with AMI, and patients with type 1 diabetes (T1D) specifically have overall worse outcomes and receive less overall revascularization.

These findings were published in Cardiovascular Revascularization Medicine.

The study included more than 2.5 million adult patients: 29,250 (1.1%) with T1D, 1,032,925 (39.9%) with type 2 diabetes (T2D), and 1,525,440 (59%) without diabetes. The mean age in each group was 59, 69, and 69, respectively. More than half of patients in each group were male, and each group was predominantly White.

These patients were included in the National Inpatient Sample (NIS) between October 2015 and December 2018.

The study authors used binomial hierarchical multilevel multivariable logistic regression with adjusted odds ratios (aOR) to investigate the association between diabetes type and AMI outcomes.

The found that, compared with patients without diabetes, patients with T1D were found to have higher odds of major adverse cardiovascular and cerebrovascular events (MACCE) (aOR, 1.20; 95% CI, 1.09-1.31), all-cause mortality (aOR, 1.20; 95% CI, 1.08-1.33), and major bleeding (aOR, 1.28; 95% CI, 1.13-1.44).

Patients with T2D also had increased odds of MACCE (aOR, 1.03; 95% CI, 1.01-1.05) and ischemic stroke (aOR, 1.09; 95% CI, 1.05-1.13), compared with patients without diabetes.

Patients with diabetes in general had lower adjusted odds of receiving percutaneous coronary intervention (PCI), with patients with T1D (aOR, 0.70; 95% CI, 0.66-0.75) having even lower odds than patients with T2D (aOR, 0.95; 95% CI, 0.94-0.96). Additionally, patients with T2D showed higher utilization of composite percutaneous and surgical revascularization compared with patients without diabetes (aOR, 1.03; 95% CI, 1.03-1.04).

While the exact reasons for these differences are unclear, the authors noted some perceived potential factors.

“It is possible that physicians' perception of DM [diabetes mellitus]-associated complications (renal dysfunction, contrast-associated nephropathy, difficult vascular access, etc.) could mediate lower adoption of invasive management,” they wrote. “Also, different unmeasured factors such as frailty status, abnormal laboratory findings, or concomitant medications (such as diuretics, anticoagulants, etc.) could contribute to these findings.

They also said, since patients with diabetes—especially T1D—are more likely to present with multivessel disease, surgical revascularization may be more preferred than percutaneous revascularization.

“Interestingly, a composite revascularization outcome (PCI/CABG [Coronary Artery Bypass Graft]) of this study was lower in T1DM patients and higher in T2DM patients, compared to their non-diabetic counterparts,” the authors said. “These important findings indicate that the lower utilization of PCI was mediated by higher utilization of CABG in T2DM patients, but underscore T1DM patients that received overall less revascularization.”

The authors noted multiple limitations to the study. Aside from limited data from the NIS dataset, the study’s retrospective design makes it impossible to fully eliminate selection bias and, despite the use of multivariable adjustments, residual confounding bias could not be fully eliminated either.

Regardless, there are several clinical implications of this study. According to the authors, the study outlines important lacking data on the differential impact between T1D and T2D, increases awareness for patients with T1D that experience worse outcomes, and warrants further studies to describe mechanisms for the observed differences between patients with T1D and T2D.

They also noted the increased awareness could improve the decision-making process by encouraging better preventive measures and advocating closer follow-up for patients with T1D and AMI.

Reference

Sethupathi P, Matetić A, Bang V, et al. Association of diabetes mellitus and its types with in-hospital management and outcomes of patients with acute myocardial infarction. Cardiovasc Revasc Med. Published online February 24, 2023. doi:10.1016/j.carrev.2023.02.008