Diabetes Often Goes Unrecognized in Patients Hospitalized With Acute MI

Diabetes is not uncommon in patients with acute MI, but in the absence of a prior diagnosis, it is likely to go undetected during hospitalization, according to a registry study published online April 21, 2015, ahead of print in Circulation: Cardiovascular Quality and Outcomes.

Given the frequency and therapeutic implications of diabetes, “consideration should be given to screening all patients with [acute MI for diabetes] during hospitalization,” say Suzanne V. Arnold, MD, MHA, of Saint Luke’s Mid America Heart Institute (Kansas City, MO), and colleagues.

The Take Home:  Diabetes Often Goes Unrecognized in Patients Hospitalized With Acute MI

Of 4,340 patients with acute MI treated at 24 US centers and enrolled in the TRIUMPH registry between June 2005 and December 2008, 30.8% had preexisting diabetes. Among the 2,854 patients without known diabetes whose hemoglobin A1c (HbA1c) level was tested in the hospital, 10.1% were identified by core lab assessment (blinded to treating clinicians) as having underlying diabetes.

Underlying diabetes was defined as the absence of known diabetes and an HbA1c level of at least 6.5%, or at least 2 fasting plasma glucose levels of at least 126 mg/dL, or a fasting plasma glucose level of at least 126 mg/dL and plasma random glucose at presentation of at least 200 mg/dL.

Only One-third of Previously Unknown Cases Detected

Of the patients with underlying diabetes, 35% were recognized by treating physicians has having the disease during hospitalization—as evidenced by provision of diabetes education for 67%, prescription of glucose-lowering drugs at discharge for 68% (48% received both interventions), or diagnosis code documentation alone in 12%.

  Patients who were white, presented with STEMI, or had multivessel CAD or higher glucose levels were more likely to undergo HbA1c screening during hospitalization. But screening rates varied considerably across hospitals, with more than a quadrupled likelihood of similar patients being screened at 1 random center than another.

Patients whose underlying disease was detected in the hospital were younger, more likely to be white, and less likely to have a history of CAD. In addition, median levels of fasting plasma glucose were higher among patients with recognized compared with unrecognized diabetes (174.5 mg/dL vs 134.9 mg/dL) as were mean HbA1c levels (8.6% vs 6.9%; both P < .001). Although all measures of glucose control were worse among patients with recognized diabetes, those with unrecognized disease nonetheless showed a wide range of glycemic control (HbA1c 6.5%-12.3%), with a considerable proportion having an HbA1c level of at least 7%.

In addition, patients whose diabetes was recognized during hospitalization were more likely to have had HbA1c testing (87.1% vs 35.5%; P < .001), and more patients with recognized diabetes had fasting and random plasma glucose levels that exceeded traditional thresholds for outpatient diagnosis of the disease. Nonetheless, 60.8% of patients whose diabetes went unrecognized had at least 1 diagnostic criterion for diabetes and 35.5% had at least 2 such criteria in their chart.

Taking Advantage of a ‘Captive Audience’

At discharge, 68.3% of patients diagnosed with diabetes during hospitalization were prescribed at least 1 glucose-lowering medication, with the majority still on therapy at 6 months. In contrast, at 6 months only 4.8% of patients with unrecognized underlying diabetes had been started on any such medication (P < .001).

“These data highlight a continued need to screen [acute MI] patients with HbA1c to improve the rate of [diabetes] recognition during the hospitalization; this would not only guide initiation of glucose management interventions (when needed) but also inform several key aspects of post-MI cardiovascular care,” the authors say. In fact, several treatment recommendations hinge on recognition of diabetes, such as the timing and type of revascularization and addition of ACE inhibitors or aldosterone inhibitors, they add.

Moreover, Dr. Arnold and colleagues observe, during the 2 or 3 days of hospitalization, acute MI patients represent “a captive audience, both more available and more receptive, making this an ideal time for [diabetes] education."

A Chance to Address Overall Health

“We already know that a large proportion of people with diabetes are not diagnosed until they have a seminal event,” Michael E. Farkouh, MD, MSc, of the Heart and Stroke Richard Lewar Centre of Excellence at the University of Toronto (Toronto, Canada), told TCTMD in a telephone interview. “In fact, the 10% figure [reported here] is actually quite low.

“What’s interesting is that about two-thirds go completely unrecognized,” he said. “And that is concerning, because these people are at high risk not only for future cardiac events but also for future noncardiac diabetic events.”

After an MI, patients are likely to receive effective therapy for ACS, so diabetes diagnosis is unlikely to have much effect on cardiovascular management and outcomes, Dr. Farkouh asserted. “But it will have a major impact on blindness, kidney disease, and other microvascular conditions, because if these patients remain unrecognized, they’re not going to be on the right medications or be monitored appropriately.”

As to why so many cases go undetected during acute hospitalization, Dr. Farkouh said that doctors treating an MI typically are not thinking about diabetes. “And sometimes the patients don’t fit the model for diabetes [in that] they are not obese,” he observed.

“But for the most part, we should be thinking about diabetes [in MI patients], particularly those in their 50s or 60s,” he said, noting that hospitalization represents an “opportunity to recognize a disease that may impact how these patients are treated down the road.” Even detection of prediabetes carries the potential for preventing progression to frank disease, he added.

The fact that US acute MI guidelines—unlike European guidelines—do not recommend diabetes screening “may be short-sighted,” Dr. Farkouh commented. “We need to think about patients as a totality. We already measure other cardiovascular markers like LDL cholesterol and blood pressure—we should be thinking about A1c, too.”

The findings “reinforce that the cardiovascular community has an opportunity to play a role in the overall health of these patients, and we should take advantage of it,” he concluded.


Arnold SV, Stolker JM, Lipska KJ, et al. Recognition of incident diabetes mellitus during an acute myocardial infarction. Circ Cardiovasc Qual Outcomes. 2015;Epub ahead of print.

Related Stories:

Diabetes Often Goes Unrecognized in Patients Hospitalized With Acute MI

  • The TRIUMPH trial was sponsored by a grant from the National Heart, Lung, and Blood Institute.
  • The current study was sponsored by a research grant from Genentech.
  • Dr. Arnold reports receiving advisory board honoraria from Novartis.
  • Dr. Farkouh reports no relevant conflicts of interest.