Post-AMI Ischemic Stroke Rates Down, Hemorrhagic Stroke Stable Since 1999

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While the risk of ischemic stroke within 1 year after acute myocardial infarction (AMI) has decreased over time among Medicare patients, rates of hemorrhagic stroke and mortality have remained stable, according to a study published online June 16, 2014, ahead of print in the American Heart Journal.

Methods
Harlan M. Krumholz, MD, SM, of Yale University School of Medicine (New Haven, CT), and colleagues gathered data on Medicare fee-for-service patients older than 65 who were subsequently hospitalized for ischemic (n = 57,848) or hemorrhagic (n = 4,412) stroke within 1 year after AMI between 1999 and 2010.

 Ischemic Stroke Rates Decreasing  

Although there was a decline in 1-year incidence of ischemic stroke over the study period, rates of hemorrhagic stroke and mortality remained stable (table 1).

Table 1. Stroke Rates, Mortality Over Time

 

1999

2004

2010

Ischemic Stroke

1-Year Incidencea

30-Day Mortality

1-Year Mortality



3.4%

19.9%

37.8%



2.8%

18.9%

36.8%



2.6%

18.3%

35.3%

Hemorrhagic Stroke

1-Year Incidence

30-Day Mortality

1-Year Mortality



0.2%

48.3%

66.6%



0.3%

53.4%

66.3%



0.2%

45.7%

60.6%

aP < .001.

The 3% risk-adjusted annual decline was similar across all age, sex, and treatment (PCI vs CABG) subgroups.

Lacking Detail  

In an email with TCTMD, Dr. Krumholz called the results of the study “remarkable.” He and his colleagues write that the results reflect improvements in treatment since 1999 including secondary prevention strategies such as statins and dual antiplatelet therapy.

Likewise, Renato D. Lopes, MD, PhD, of Duke University Medical Center (Durham, NC), told TCTMD in a telephone interview the study allows clinicians to have a contemporary look at stroke after AMI in a very large patient population. However, he added that studies based on large databases tend to lack some of the granularity that is necessary to give the data perspective.

Many patients younger than the study’s patient population also have AMI and subsequent stroke, Dr. Lopes reported.

In addition, the study did not include information differentiating MI type, in-hospital stroke occurrence, strokes that did not require hospitalization, or antiplatelet therapy, he said.

New Therapies Available  

Eric R. Bates, MD, of the University of Michigan Medical Center (Ann Arbor, MI), agreed that there was a lack of detailed information in the study. He told TCTMD in a telephone interview that the data should be interpreted with caution and is not generalizable to an all-comers stroke patient population.

In addition, he pointed out that several years have elapsed since the study ended. “It may claim that it is a recent, modern cut of the data, but you could argue that things have changed a lot in the last 4 years with the approval of prasugrel and ticagrelor,” Dr. Bates observed.

Dr. Lopes agreed, adding that newer, more potent antiplatelets may have decreased stroke rates further. “It will be important to see trends from 2010 to 2014 and to examine how many patients used clopidogrel and aspirin versus the newer agents,” he said.


Source:
Wang Y, Lichtman JH, Dharmarajan K, et al. National trends in stroke after acute myocardial infarction among Medicare patients in the United States: 1999-2010. Am Heart J. 2014;Epub ahead of print.

 

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Disclosures
  • Dr. Krumholz reports receiving institutional research grants from Johnson &amp; Johnson and Medtronic.
  • Drs. Bates and Lopes report no relevant conflicts of interest.

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