scarcely any predictors of systemic embolism in patients with mitral stenosis have been identified by way of noninvasive methods.

scarcely any predictors of systemic embolism in patients with mitral stenosis have been identified by way of noninvasive methods. This study used the principally powerful noninvasive diagnostic tool, transthoracic echocardiography, as well as other noninvasive clinical information to anticipate for predictors. Five hundred consecutive patients with a mitral valve area of 2 [cmsup2] or les were studied. They were divided into sum of two units groups: group 1 consisted of 143 patients with a history of systemic embolism and clump 2 consisted of 357 patients with no history of systemic embolism. Using a stepwise logistic regression upon a random subsample of 400 patients, 4 independent predictors were found: the appearance of atrial fibrillation (p=0.003, relative risk [RR]=23 95% CI=1.3, 42) the absence of significant tricuspid regurgitation (p=0008 RR=25 95% CI=1.3, 49) the absence of aortic regurgitation (p=0022 RR=22 95% CI=I.1.1 42) and the nearness of left atrial smoky echoe (p=0039 RR=17 95% CI=1.1, 30) When the above example together with significant interaction space of times was applied to the remaining 100 patients, the couple the Hosmer-Lemeshow and Brown goodness-of-fit statistics were not significant (p=0888 and p=0248 respectively), indicating that the fit was adequate and the prototype was validated. Thus, important noninvasive predictors of systemic embolism in patients with mitral stenosis can easily be obtained. Subgroup of patients with high risk of systemic embolism can be identified. This may refine our therapeutic strategies to stop the catastrophe of systemic embolism.

Af=atrial fibrillation; AR=aortic regurgitation; CHF= congestive heart failure; LA=Ieft atrial; 2-D=two-dimensional; LADs=left atrial diameter at end-systole; MR=mitral regurgitation; MS=mitral stenosis; MVA=mitral valve area; PR=pulmonary regurgitation; RR=relative risk; TR=tricuspid regurgitation

Systemic embolism befalls in 9 to 49 percent of patients with rheumatic heart disease who were followed up above several years, with the average being 15 to 20 percent[1] It is individual of the most important complications in patients with mitral stenosis (MS) because of the associated morbidity and mortality.[1,2] hardly any predictors of a noninvasive nature, however, have been identified. This studious mood used the most powerful noninvasive diagnostic tool, transthoracic echocardiography, as well as other noninvasive clinical information to apply the mind for any possible predictors.

METHODS

thought Patients

Consecutive patients with rheumatic M who were referr for echocardiographic examination and with a valve area of 2 [cmsup2] or les (as determined by means of two-dimensional [2-D] echocardiograms or Doppler constraining force half-time method) were enrolled in the investigation The reasons for the referral for resound examination included the presence of continuous sound heart failure, stroke, peripheral embolism, cardiomegaly, or abnormal electrocardiogram. Those with a prior history of exhibit heart surgery or percutaneous balloon mitral commissurotomy were exclud There were 500 patients, consisting of 331 women and 169 men Their age ranged from 17 to 95 years with a mean of 49 (SD=13) The studious mood was mainly a retrospective analysis of medical information. To be specific, all patients' histories were researched carefully according to personal interviews and a detailed review of their hospital records for any signs or laboratory evidence of systemic embolism (eg angiography, operative findings, etc) There were 143 patients with a history suggestive of systemic embolism (group 1) and 357 patients without any history of systemic embolism (group 2) Five clinical variables were examined, including age, sex the carriage or absence of atrial fibrillation (Af) (sustained or paroxysmal), systemic hypertension, and significant congestive heart failure (CHF) (defined as fresh York Heart Association class 3 or 4) The status of anticoagulant therapy was not included in the analysis for the following reason. Although an anticoagulant was used in 43 percent (61/143) of dispose 1 and 11 percent (41/357) of arrange 2 patients, 54 (89 percent) of the 61 users of anticoagulant in collection 1 received anticoagulant therapy after the affair of embolism. Therefore, the higher prevalence of anticoagulant therapy in clump 1 was the result rather than the cause of embolism.

Echocardiography

undivided echocardiographic and Doppler studies were performed with a sonos 1000 machine (Hewlett-Packard) using 25 MHz and 5 MHz transducers from the transthoracic windows. Ten echocardiographic variables were examined. The mitral valve area (MVA) was planimetered from the 2-D echocardiogram. When the 2-D reverberate of the mitral orifice was unsatisfactory (consisting of 3 percent of the patients studied), then we resorted to the hurry half-time ([T.sub.1/2]) method (mitral orifice area [[CMsup2]]=220/[Tsub1/2] ms)[3-5] We did not use the constraining force half-time method when the mitral areas could be defined clearly on 2-D echo, because it has been shown that the constraining force half-time is influenced by a variety of factors other than the mitral orifice area. These factors include heart rate, the vicinity of associated aortic regurgitation, chamber compliance, etc[67] In addition to the mitral valve area, echocardiographic variables included the left atrial diameter at end-systole (LAD), the carriage or absence of LA thrombus (sensitivity 63 percent specificity 95 perceent positive predictive value 84 percent negative predictive value 83 percent)[8] or LA fumid echoes,[9-11] the presence or absence of impaired left ventricular systolic performance, and the demeanor or absence of significant (defined as more than a mild standing of) aortic stenosis (AS), aortic regurgitation (AR), mitral regurgitation (MR) tricuspid regurgitation (MR) and pulmonary regurgitation (PR) The extent of these valvular lesions was semiquantified with continuity equation (for AS) or color-flow mapping (for various regurgitations) as previously described.[12,13] Briefly, a significant AS attributes to an aortic valve area of 12 [cmsup2] or les at continuity equation method,[12] a significant MR or TR deliver overs to an MR jet area to LA area ratio or TR jet area to RA area ratio of 20 percent or more, and a significant AR or PR appertains to a jet width to ventricular efflux tract diameter ratio of 25 percent or more.[13] Left atrial diameter at end-systole was measured from the M-mode echocardiogram recorded in the parasternal long-axis view. The measurement was made according to the American Society of Echocardiography recommendations.[14] For the sense of detecting LA smoky echoe we used a 5 MHz transducer since it has a greater sensitivity than a 25 MHz transducer.[9] We used "smoky echoes" instead of "spontaneous reverberation contrast," which has been commonly used in other studies. This was because a patients with severe TR or right heart failure had bright moving flaws in the inferior vena cava or hepatic veins identical to those appearing in contrast echocardiography. Hence, we reserv spontaneous resound contrast for that echo pattern and used fumy echoes for the finer, lighter whorling echoe that appeared in the LA of patients with unadorned MS. In this echocardiography laboratory, the intraobserver variability for LA fuliginous echoes was 7 percent, and the interobserver variability was 10 percent

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