Mitral valve prolapse and cerebral ischemic events. A comparison between a neurology population with stroke and a cardiology population with mitral valve prolapse observed for five years

Lack of evidence of an association between mitral-valve prolapse and stroke in young patients

BACKGROUND

Previous studies have reported a high prevalence of mitral-valve prolapse among patients with embolic stroke (28 to 40 percent), especially among young patients (those < or =45 years old); this finding has practical implications for prophylaxis. However, diagnostic criteria for prolapse have changed and are now based on three-dimensional analysis of the shape of the valve; use of the current criteria reduces markedly the frequency of such a diagnosis and increases its specificity. Previously described complications must therefore be reconsidered.

METHODS

In a case-control study, we reviewed data on 213 consecutive patients 45 years old or younger with documented ischemic stroke or transient ischemic attack between 1985 and 1995; they underwent complete neurologic and echocardiographic evaluations. The prevalence of prolapse in these patients was compared with that in 263 control subjects without known heart disease, who were referred to our institution for assessment of ventricular function before receiving chemotherapy.

RESULTS

Mitral-valve prolapse was present in 4 of the 213 young patients with stroke (1.9 percent), as compared with 7 of the 263 controls (2.7 percent); prolapse was present in 2 of 71 patients (2.8 percent) with otherwise unexplained stroke. The crude odds ratio for mitral-valve prolapse among the patients who had strokes, as compared with those who did not have strokes, was 0.70 (95 percent confidence interval, 0.15 to 2.80; P=0.80); after adjustment for age and sex, the odds ratio was 0.59 (95 percent confidence interval, 0.12 to 2.50; P=0.62).

CONCLUSIONS

Mitral-valve prolapse is considerably less common than previously reported among young patients with stroke or transient ischemic attack, including unexplained stroke, and no more common than among controls. Using more specific and currently accepted echocardiographic criteria, therefore, we could not demonstrate an association between the presence of mitral-valve prolapse and acute ischemic neurologic events in young people.

Acute homonymous field loss: really a diagnostic dilemma

A young woman developed the sudden onset of a congruous right lower quadratic visual field defect two weeks prior to examination. The remainder of her history and physical examination were noncontributory. Discussion revolves around the differential diagnosis of retro chiasmal field defects in young individuals. An MRI scan was most compatible with the diagnosis of disseminated sclerosis.

Transient visual symptoms and carotid artery disease. Exploration by real-time B-mode echotomography

The real-time B-mode echotomographies of 100 patients with transient visual symptoms have been reviewed and their findings have been compared with those of other 100 patients with transient ischemic attacks, who never had visual disturbances in their clinical history. The rate of pathologic echotomographies was higher in the group of patients with transient visual symptoms (72%), who also had a higher percentage (50% of the positive cases) of small or mild plaques without significant hemodynamic effects. The amaurosis fugax, particularly when associated with hemispheric ischemic symptoms, should suggest a carotid disease. The non-invasive exploration by real-time B-mode echotomography and Doppler with spectral analysis is the method of choice for the diagnosis of patients with transient visual symptoms.

Neurologic aspects of mitral valve prolapse

Mitral valve prolapse (MVP), the most frequently encountered valvular condition in the population, has been reported in an increasing variety of neurologic, muscular, and psychiatric disorders during the last twelve years. Extensive review of reports indicates this has resulted from observations of either (1) inordinate incidence of MVP in well-defined neurologic entities or (2) development of neurologic or ophthalmologic complications attributed to MVP. In the review presented, basis is found for categorizing MVP by its association with (1) well-defined, genetically determined neurologic disorders; (2) disorders characterized by structural abnormalities, many genetically determined, or inflammatory processes of connective tissues; (3) "mechanical" prolapse resulting from disproportion of mitral valve annulus and left ventricular size, which is, at times, reversible; and (4) a generally asymptomatic state that, at times, is associated with ischemic, thrombotic, embolic, and infectious disorders of the brain and eye. The paradox between the large number of persons with MVP in the general population who remain healthy and a subpopulation of patients with complications of MVP (eg, stroke) or other entities has been identified. A second paradox is found between the well-known increased incidence of MVP, especially in young patients with stroke, and the apparent rarity of stroke among patients with both common (eg, migraine) and unusual (eg, myotonic dystrophy) neurologic entities in which an extraordinary high prevalence of MVP is known to exist.

Internal carotid artery occlusion in a young female with mitral valve prolapse

A healthy 28 year old housewife presented with sudden right hemiplegia and aphasia. No predisposing factors could be ascertained apart from posterior cusp mitral value prolapse on two dimensional echocardiography. Extensive investigations confirmed the presence of cerebral infarction and persistent occlusion of the left internal carotid artery near its origin.

Platelet function and coagulation studies in patients with mitral valve prolapse

Twenty-eight consecutive patients with mitral valve prolapse (MVP), seven of whom had previous cerebrovascular disorders (CVD), were studied for platelet function and coagulation tests. While platelet function tests were found to be normal with the exception of platelet aggregation rate (PAR), there was a significant rise of factors VIII vWF:Ag (Von Willebrand) and (FPA) fibrinopeptide A. Six cases had high levels of both these factors, suggesting the existence of a particular subset of patients with MVP, with a higher risk of thromboembolic episodes, although only three out of seven patients with previous CVD had either FPA or VIII vWF:Ag levels. The broad spectrum of subjects with MVP probably explains the different results obtained when studying platelet function and coagulation factors. Therefore, larger population studies and prolonged follow-up of cases with either coagulation abnormalities similar to the ones found in the present report and/or altered platelet function tests are suggested to discover if it is possible to detect patients with a potential for thromboembolism.

Echocardiographically documented mitral-valve prolapse. Long-term follow-up of 237 patients

We determined the long-term prognosis for patients with mitral-valve prolapse documented by echocardiography by following 237 minimally symptomatic or asymptomatic patients for a mean of 6.2 years (range, 1 to 10.4). The actuarial eight-year probability of survival was 88 per cent, which is not significantly different from that for a matched control population. An initial left ventricular diastolic dimension exceeding 60 mm was the best echocardiographic predictor of the subsequent need for mitral-valve replacement (17 patients). Of the 97 patients with redundant mitral-valve leaflets identified echocardiographically, 10 (10.3 per cent) had sudden death, infective endocarditis, or a cerebral embolic event; in contrast, of the 140 patients with nonredundant valves, only 1 (0.7 per cent) had such complications (P less than 0.001). Most patients with echocardiographic evidence of mitral-valve prolapse have a benign course, but subsets at high risk for the development of progressive mitral regurgitation, sudden death, cerebral embolic events, or infective endocarditis can be identified by echocardiography.

Cerebral ischemic attacks as a complication of aortic and mitral valve prolapse

The high incidence of mitral valve prolapse (MVP) in patients with ischemic attacks is puzzling when compared with the very low incidence of cerebrovascular attacks observed in individuals known to have MVP. Our aim was to determine if it is possible to identify a patient subset with MVP at the highest risk of embolization on the basis of 2D-echocardiographic findings. We compared the echocardiographic picture of a group of 39 patients with MVP and cerebral ischemic attacks (29 TIAs, 10 strokes) in the carotid territory, without any pathological lesions at angiography, with that of a control group of 111 patients with MVP without neurological complications. The two groups were not different for age or sex. Patients with MVP and neurological complications showed a higher prevalence of aortic valve prolapse (62% vs 34%, p less than 0.01), of an association between valvular diffuse thickening and aortic valve prolapse (54% vs 23%, p = 0.001), and of multiple valve prolapse with valvular diffuse thickening (26% vs 7%, p less than 0.01) than those of the control group. This study suggests that in young people cerebral ischemic events could be related to the presence of a combined valve prolapse and to an echocardiographic picture of valve diffuse thickening. These data suggest that in this selected group with multiple valve prolapse and valvar diffuse thickening prophylaxis against embolic events by pharmacological preventive measures should be considered.