ESC: Risk of ischemic stroke after acute MI is dropping

The risk of ischemic stroke after an acute MI fell by 21 percent over a decade, according to an analysis of Swedish registry data. The results suggest that improvements in the care of acute MI patients may be driving down the incidence in ischemic stroke.

The results were presented Aug. 28 at the European Society of Cardiology Congress in Munich in a poster session by Anders Ulvenstam, MD, of Östersund Hospital in Östersund, Sweden.

Ulvenstam and colleagues observed that treatment for acute MI has improved over the past 10 years with advancements in antithrombotic, lipid-lowering and reperfusion therapies but it was unknown if changes in care had affected the incidence of stroke. To explore that question, they used the Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA) database.

The researchers identified 173,233 Swedish patients who experienced an acute MI between 1998 and 2008. To determine who among those patients suffered a stroke, they merged the data with the Swedish National Registry. That registry holds diagnoses for all patients at discharge from a hospital.

“Many studies have been conducted within clinical trials but these trials tend to focus on a particular patient group,” Ulvenstam said in a release. “Few, if any, studies have been done on the broader group of patients seen in day-to-day clinical practice.”

They found that the average risk of ischemic stroke at one year after an acute MI (AMI) was 4.1 percent. The risk of ischemic stroke dropped by 21 percent over a 10-year period, from 4.7 percent in 1998 to 2000 to 3.8 percent in 2007 to 2008. A secondary analysis found that reperfusion therapy with PCI, fibrinolysis, thrombocyte aggregation inhibitors (aspirin and P2Y12-inhibitors) and statins independently reduced the risk of stroke.

Ulvenstam and colleagues noted that the average one-year risk of stroke after AMI found in their study was nearly twice the average risk reported in other literature. They attributed the difference to the breadth of the registry data. Their findings suggest that the risk of stroke may be diminishing.

“This is probably a direct result of the great improvement in AMI care which has taken place during the last two decades,” Ulvenstam said. “For the first time we can see the impact of different drugs and interventional procedures on stroke risk after AMI.”