The New York Islands AVM Study

Background and Purpose— Prospective population-based data on the incidence of brain arteriovenous malformation (AVM) hemorrhage are scarce. We studied lifetime detection rates of brain AVM and incident AVM hemorrhage in a defined population. Methods— The New York islands (ie, Manhattan Island, Staten Island, and Long Island) comprise a 9 429 541 population according to the 2000 census. Since March 15, 2000, all major New York islands hospitals have prospectively reported data on consecutive patients living in the study area with a diagnosis of brain AVM and whether the patient had suffered AVM hemorrhage. Patients living outside the ZIP code–defined study area were excluded from the study population. Results— As of June 14, 2002, 284 prospective AVM patients (mean±SD age, 35±18 years; 49% women) were encountered during 21 216 467 person-years of observation, leading to an average annual AVM detection rate of 1.34 per 100 000 person-years (95% CI, 1.18 to 1.49). The incidence of first-ever AVM hemorrhage (n=108; mean age, 31±19 years; 45% women) was 0.51 per 100 000 person-years (95% CI, 0.41 to 0.61). The estimated prevalence of AVM hemorrhage among detected cases (n=144; mean age, 33±19 years; 50% women) was 0.68 per 100 000 (95% CI, 0.57 to 0.79). Conclusions— Our prospective data, spanning 27 months, suggest stable rates for AVM detection and incident AVM hemorrhage. Approximately half of AVM patients may suffer intracranial hemorrhage.