According to a study published in Neurology, silent myocardial infarction (MI) is associated with the subsequent occurrence of ischemic stroke in the elderly.
In this prospective cohort study, the researchers enrolled 5888 patients in the cardiovascular health study between 1989 and 1993. Patients were eligible regardless of whether they were diagnosed with heart disease. A total of 5888 participants were recruited (cohort 1: 5201; cohort 2: 687). Only data from cohort 1 were included in the primary analyzes, although both participants in cohort 1 and cohort 2 were included in the sensitivity analyzes.
Follow-up (median 9.8 years) comprised annual appointments and half-yearly phone calls. Researchers collected data on cardiovascular events and medical histories; this information has been evaluated by evaluation panels.
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Incidence of ischemic stroke was designated as the primary endpoint and was divided into 4 categories: lacunar stroke, stroke due to atherosclerosis of a major artery, cardioembolic stroke, and stroke for other / unknown reasons. These were determined by the jury committees and resulted in a statistical kappa reliability value of 0.77.
A total of 4224 participants were included in the primary analysis. The incidence of open MI was 10% (n = 421), silent MI 8.6% (n = 362), and ischemic stroke 8.9% (n = 377). Of the 10% of patients who experienced open MI, 0.5% (n = 23) had previously silent MI. Of the 8.9% of patients in whom a stroke was reported, 15.1% (n = 57) were classified as lacunar, 36.1% (n = 136) as non-lacunar and 48.8% (n = 184 ) as other / unknown classification.
Overall, there was a significant association between MI with a silent manifestation and the occurrence of a subsequent ischemic stroke (hazard ratio [HR], 1.51; 95% CI, 1.03-2.21). After adjustments for demographics and risk factors, secondary analyzes showed a significant association between silent MI and non-lucunal-type strokes (HR 2.40; 95% CI 1.36-4.22), but not with other / unknown ischemic strokes (HR 1 , 29; 95% CI, 0.73-2.31). Sensitivity analyzes were consistent with these results.
There was also a significant association between overt MI and both incidental and non-lacunar ischemic strokes, short-term (HR 80; 95% CI 53-119 and HR 210; 95% CI 127-348) and long-term (HR, 1, 60; 95% CI 1.04-2.44 and HR, 2.21; 95% CI, 1.16-4.22).
A potential limitation of this study is that Cohort 2 was excluded from the primary analysis because data from Cohort 1 were available over a longer period of time. However, since Cohort 1 consisted mainly of white participants and the majority of Cohort 2 consisted of black participants, additional research would help confirm the generalization of this study to a diverse population.
The authors of the study concluded that “the association between silent MI and incident ischemic stroke is consistent with the hypothesis that silent MI can lead to thrombus formation and subsequent cardiac embolism, as with overt MI.” Ultimately, “although MI is silent or undetected it should not be viewed as benign, but rather as a hidden risk factor for many adverse outcomes. “
Disclosure: Several study authors stated links with pharmaceutical companies. For a full list of the author’s disclosures, see the original reference.
reference
Merkler AE, Bartz ™, Kamel H, et al. Silent myocardial infarction and subsequent ischemic stroke in the Cardiovascular Health Study. Neurology. Published online May 24, 2021. doi: 10.1212 / WNL.000000000000012249
This article originally appeared on The Cardiology Advisor
