News

AHA Calls for Glucose Control in ACS Patients With Hyperglycemia


 

Hyperglycemia is common in acute coronary syndrome and is a strong predictor of poor outcome, but many questions remain about how to take these facts into account in clinical practice, according to a scientific statement from the American Heart Association.

Although it's still uncertain whether treating hyperglycemia in acute coronary syndrome (ACS) produces definite benefits, it's reasonable to consider intensive glucose control in patients with plasma glucose levels above 180 mg/dL, and even for some patients with milder degrees of hyperglycemia, according to the members of the writing group, led by Dr. Prakash Deedwania of the University of California, San Francisco (Circulation 2008 Feb. 25 [doi:10.1161/circulationaha.107.188629]).

“Most cardiologists are not aware of the importance of hyperglycemia in the acute coronary syndrome,” Dr. Deedwania said in an interview. “Although some specialty centers are taking care of hyperglycemia, the majority of them are not paying any attention.”

More than 2 million patients are treated in the United States annually for ACS, and as many as 50% of them might have hyperglycemia, Dr. Deedwania said. Numerous analyses and meta-analyses have found increased risks linked to hyperglycemia in ACS. The largest retrospective study, which involved 141,680 patients, found that hyperglycemia increased the risk of 30-day mortality by 13%–77%, and it increased 1-year mortality by 7%–46%, depending on the degree of hyperglycemia.

The risks appear to be greatest in hyperglycemic patients with no previous evidence of diabetes, but it's still unclear whether hyperglycemia is a marker or a mediator of adverse outcomes.

The most pressing unanswered question, according to Dr. Deedwania, is to determine which treatment for hyperglycemia has the best combination of efficacy and safety. One large recent trial showed that hypoglycemia can be more dangerous than hyperglycemia, so it's important to figure out how critical it is to control hyperglycemia and to what extent it should be controlled.

Other areas in need of further investigation include whether persistent hyperglycemia during ACS hospitalization has a greater impact on prognosis than does admission hyperglycemia alone, whether there is a critical period of vulnerability from hyperglycemia in these patients, whether the best target glucose levels differ in patients with and without pre-existing diabetes, and what the optimal timing of therapy might be.

Meanwhile, the writing group determined that there is now excellent (level A) evidence to recommend that glucose levels should be part of the initial laboratory evaluation in all patients with suspected or confirmed ACS. And there is good (level B) evidence that glucose levels should be monitored closely in patients admitted to an ICU with ACS, that it's reasonable to consider treatment in patients with high levels of hyperglycemia, that insulin by intravenous infusion is the most effective measure to control glucose in ICU patients, and that special attention should be paid to ACS patients with hyperglycemia but no history of diabetes.

In addition to informing physicians about the importance of hyperglycemia in ACS, the release of the AHA scientific statement has another goal, Dr. Deedwania said. “This is a call to action for all the different agencies such as the National Institutes of Health to consider doing trials on some of these very specific questions. This should be a priority.”

Recommended Reading

Diabetes Raises Mortality in ACS Patients
MDedge Cardiology
Post-MI Depression Affects More Women Than Men
MDedge Cardiology
Daily Breathing Protocol Reduced Time Patients Spent in ICU
MDedge Cardiology
Elevated Cystatin C Is Harbinger of Adverse Events in ACS
MDedge Cardiology
Aspirin Responsiveness Lowered in ACS Patients?
MDedge Cardiology
GIK Infusion Not Beneficial and Possibly Harmful in STEMI
MDedge Cardiology
'False-Positive' Cath Lab Activation for STEMI Up to 14%
MDedge Cardiology
ED Crowding Worsens Outcomes of Potential ACS
MDedge Cardiology
Aspirin Resistance Attributed to Noncompliance
MDedge Cardiology
CD34+ Stem Cell Transplant Helps in Refractory Angina
MDedge Cardiology