RISK OF STROKE IN ADULTS WITH CYANOTIC CONGENITAL HEART-DISEASE

Background. Adults with cyanotic congenital heart disease and elevated hematocrit levels are often phlebotomized because of an assumed risk of cerebral arterial thrombotic stroke. Whether a relation exists betw een hematocrit level, symptomatic erythrocytosis (hyperviscosity), and stroke remains to be established in this patient population. Methods and Results. Accordingly, 112 cyanotic patients 19-74 years old (mean, 36 +/- 11.7 years) in the UCLA Adult Congenital Heart Disease Center Registry were selected for study by virtue of continuous observation f or 1-12 years (total, 748 patient-years). Patients with independent ri sk factors for embolic or vasospastic stroke were excluded. The study patients were then divided into two groups: 1) compensated erythrocyto sis (stable hematocrit levels of 46.0-72.7% [mean, 57.5 +/- 7.2%], iro n replete, absent or mild hyperviscosity symptoms), and 2) decompensat ed erythrocytosis (unstable rising hematocrit levels of 61.5-75.0% [me an, 69.5 +/- 10.6%], iron deficiency, marked-to-severe hyperviscosity symptoms). No patient with either compensated or decompensated erythro cytosis, irrespective of hematocrit level, iron stores, or the presenc e, degree, or recurrence of cerebral hyperviscosity symptoms, progress ed to clinical evidence of a completed stroke (cerebral arterial throm bosis with brain infarction). Conclusions. Because a risk of stroke ca used by cerebral arterial thrombosis was not demonstrated, because the circulatory effects of phlebotomy are transient, and because of the u ntoward sequelae of phlebotomy-induced iron deficiency, we recommend p hlebotomy for the temporary relief of significant, intrusive hypervisc osity symptoms but not for the hematocrit level per se. According to o ur data, phlebotomy is not warranted to reduce an assumed risk of stro ke because that risk did not materialize.