Risk of myocardial infarctions is increased in patients with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is one of the most common genodermatoses and multiorgan syndromes, with an incidence of about 1:2000. According to our hypothesis, NF1 is associated with comorbidities not yet recognized. Case reports on myocardial infarctions in NF1 have reported coronary artery aneurysms and pheochromocytomas as underlying causes, while no epidemiologic data on the incidence of heart infarctions in NF1 has been available. We have used the total population based Finnish cohort of 1410 NF1 patients to analyze the incidence of myocardial infarctions. The control population consisted of 10 persons per patient, stratified according to gender, birth year and municipality. The incidence of myocardial infarctions was followed from the Care Register for Health Care, maintained by National Institute for Health and Welfare. The Register collects information of all outpatient visits and ward treatments in hospitals in Finland. The register was searched for ICD-10 codes I21 and I22 and ICD-9 code 410. Twenty-six myocardial infarctions were observed among NF1 patients, yielding odds ratio (OR) of 1.7 (95% CI 1.1-2.5) compared to the matched controls. The median age at the first hospital visit with myocardial infarction was 66.8 years (range 52.4-91.8). Eleven of the patients were women (OR 2.1, 95% CI 1.1-4.1) and 15 were men (OR 1.4, 95% CI 0.8-2.5). Other diagnoses observed among the NF1 patients with myocardial infarction included chronic ischemic heart disease (18/26), angina pectoris (11/26), pneumonia (11/26), heart failure (10/26), cerebral infarction (9/26) and essential hypertension (9/26). This preliminary data indicates that at least women with NF1 have an increased risk for myocardial infarctions, and their underlying causes require further investigation. The results emphasize the need of tailored follow-up of NF1 patients.