From the Guidelines

Cardiomyopathy is a significant risk factor for stroke, even in the absence of atrial fibrillation.

The risk of stroke is inversely proportional to the cardiac ejection fraction, with a decline in ejection fraction increasing the risk of stroke 1.
Cardiomyopathies, including diseases of the atria and ventricles, can increase the risk of stroke due to structural, electrophysiological, and serum biomarker abnormalities that can lead to thrombus formation and embolization 1.
The incidence of stroke is higher in patients with left ventricular systolic dysfunction, with an estimated 72,000 initial stroke events per year associated with left ventricular systolic dysfunction 1.
The use of warfarin for cardioembolic prophylaxis in patients with reduced left ventricular ejection fraction in the setting of idiopathic cardiomyopathy remains controversial, with some studies suggesting a reduction in stroke risk, but others showing no significant benefit 1.

Aspirin has been shown to reduce the stroke rate by 20% in patients with cardiomyopathy 1.
Warfarin may be prescribed to prevent cardioembolic events in patients with cardiomyopathy, but its efficacy and safety are still being studied 1.
The primary objective of management is to reduce the risk of stroke and other thromboembolic events, while also managing the underlying cardiomyopathy and its symptoms.

From the Research

The relationship between stroke and cardiomyopathy is complex, with various studies indicating a significant association between the two conditions.

Cardiomyopathies, including hypertrophic and dilated cardiomyopathy, can increase the risk of stroke due to embolic events, particularly in patients with atrial fibrillation 2, 3, 4.
The incidence of stroke in patients with hypertrophic cardiomyopathy can be as high as 1.0% per year, with older age and enlarged left atrial dimension being independent determinants of embolic events 4.
Severe left atrial dilatation is a powerful risk factor for stroke in patients with hypertrophic cardiomyopathy, regardless of the presence of atrial fibrillation 3, 4.
Cardiomyopathies can also lead to stroke-like episodes, which are unique to mitochondrial disorders and have a different pathogenesis, clinical presentation, and imaging characteristics compared to ischemic stroke 5.
Secondary cardiomyopathies, which occur as part of a neuromuscular disorder, can also increase the risk of stroke, with ischemic stroke being the most common neurological disease caused by cardiomyopathies 6.

Several risk factors and mechanisms contribute to the relationship between stroke and cardiomyopathy, including:

Atrial fibrillation, which can increase the risk of stroke by a factor of four to seven times compared to normal sinus rhythm 2.
Left ventricular dysfunction, which can lead to mural thrombi and embolic strokes 2.
Severe left atrial dilatation, which is a powerful risk factor for stroke in patients with hypertrophic cardiomyopathy 3, 4.
Genetic abnormalities, which can increase the risk of cardiomyopathy and subsequent stroke 2.

The relationship between stroke and cardiomyopathy has significant clinical implications, including:

The need for early cardiologic investigations and close follow-ups in patients with neuromuscular disorders 6.
The importance of avoiding muscle-toxic medication in patients with cardiomyopathy and a diagnosed neuromuscular disorder 6.
The potential benefit of primary stroke prevention in patients with cardiomyopathy, although further research is needed to determine which patients would profit most from this approach 6.