Small abnormal echos after mitral valve replacement with bileaflet mechanical prostheses: predisposing factors and effect on thromboembolism.

Early transesophageal echocardiography (TEE) after mitral valve replacement can detect symptomless, non-obstructive thrombus on prosthetic valves and also small filamentous abnormal echoes (SAE). The object of this study is to evaluate their respective frequency and predisposing factors. Between October 1988 and June 1992, 129 consecutive patients underwent mitral valve replacement with a bileaflet prosthesis and had transesophageal echocardiography at an average of 15 +/- 7 days (range: 6-35 days) after surgery. Details of postoperative anticoagulation were analyzed in 99 patients from five surgical centers having comparable postoperative anticoagulation protocols. Among those patients presenting with SAE, 76% had a second transesophageal echocardiography at an average of 145 +/- 166 days after the first examination. Mean age was 56 +/- 13 years. Small filamentous echoes were found in 55 patients (43%). In univariate analysis, independent predictors were age, absence of systolic regurgitation across the mitral prosthesis as observed with continuous Doppler, and the presence of spontaneous echo contrast (SC) in the left atrium: 54 +/- 14 years in the absence vs. 59 +/- 10 in the presence of SAE (p < 0.05); 54% of systolic leak vs. 36% (p < 0.05); 43% of SC vs. 75% (p < 0.00001). In multivariate analysis, spontaneous echo contrast was the only independent predictor for SAE (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognosis of valve replacement for aortic stenosis with or without coexisting coronary heart disease: a comparative study.

Between January 1978 and June 1992, 798 patients underwent isolated AVR for hemodynamically significant calcific aortic stenosis. Preoperative coronary angiography was performed in 687 patients, of whom 229 had coronary stenosis > 40% and were divided into three (I, IIa and IIb) groups. Group I consisted of 144 patients undergoing AVR plus coronary artery bypass grafts (CABG); 39 patients in Group IIa had AVR only in the presence of coronary stenoses < 60%, and 46 patients in Group IIb had AVR only in the presence of coronary stenoses > 60%. Group III consisted of 144 matched patients selected from the remaining 458 patients with no coronary disease, or stenoses less than 40%, according to five matching criteria (age, sex, functional status, ejection fraction and year of surgery) with patients in Group I. Early mortality was 10.4% in Group I, 7.7% in Group IIa, 13% in Group IIb and 4.9% in Group III. Although the differences in operative mortality are apparent, they did not reach statistical significance. A difference in long term survival could only be detected between Groups I and III (actuarial survival at nine years 66% and 78.9%, respectively, p < 0.01). Similarly, late coronary events were more frequent in Group I than in Group III (13.9% vs. 5.1%, p < 0.03). It is concluded that revascularization should be as complete as possible for severe coronary stenoses coexisting with significant calcific aortic stenosis. However, bypassing of moderate coronary lesions (stenoses in the order of 50%) in association with AVR does not appear justified on current evidence. Further studies on this important aspect are clearly required.

[Prognosis after aortic valve replacement for aortic valve stenosis with or without associated coronary lesions]. / Pronostic après remplacement valvulaire aortique pour rétrécissement aortique avec ou sans lésions coronaires associées.

With the increasing age of patients and the progression of degenerative pathologies, the management of aortic stenosis (AS) with coronary artery disease is becoming more frequent. Reported results of combined valve and coronary surgery are equivocal especially with respect to the increased risk compared with aortic valve replacement without coronary surgery. The authors assessed the results of combined surgery by comparing two groups of patients with AS operated between 1979 and 1991: 122 patients with coronary lesions undergoing combined valve and coronary surgery (Group I) and 122 patients without coronary artery disease undergoing isolated aortic valve replacement (Group II) and paired with Group I patients for 5 prognostic factors (age, sex, functional status, date of surgery and left ventricular ejection fraction). Pairing the patients provided comparable populations for these 5 factors. The average age was high (68 years in Group I with over 50% of patients over 70 years of age) and most patients were in functional classes III or IV (67% in Group I). In Group I, 67% of patients had multivessel disease (average 2 vessel disease). Aortic valve replacement was associated with an average of 1.7 coronary bypass grafts per patient. Myocardial protection was the same in all cases using cold potassium enriched cardioplegic solutions. Operative mortality was 10.6% in Group I compared with 4.9% in Group II (NS) and the respective perioperative infarction rates were 6.6% and 0.8% (p < 0.02). Seven year actuarial survival rates were 71.8% in Group I and 74.9% in Group II (NS) without any increased late mortality in Group II.(ABSTRACT TRUNCATED AT 250 WORDS)

[Early transesophageal echocardiography after mitral valve replacement. Significance of minor abnormal signals]. / Echocardiographie transoesophagienne précoce après remplacement valvulaire mitral. Signification des petits échos anormaux.

The aim of this study was to determine the frequency, significance and prognosis of small, abnormal, strand-like echos observed by early transoesophageal echocardiography after mitral mechanical valve replacement with hemi-disc prostheses. One hundred and twenty nine consecutive patients operated between October 1988 and June 1992 underwent transoesophageal echocardiography on average 15 +/- 7 days after surgery. A second transoesophageal echocardiography was performed in 52 patients on average 8 months after the first postoperative examination. The frequency of small strand-like echos and of non-obstructive thromboses of the valve at the initial transoesophageal examination was 43% and 8.5% respectively. A multivariate analysis showed that the only independent predictive factor for prosthetic valve strands was spontaneous intra-atrial contrast (p < 0.01). The presence of strands was significantly related to the prevalence of early thrombo-embolic events (confirmed non-obstructive valve thrombosis and systemic embolism). Strands were observed in 80% of cases with early thromboembolic complications compared with only 38% of cases with no early thromboembolic events (p < 0.04). Univariate analysis showed that the protamine/heparin ratio at the end of cardiopulmonary bypass and the percentage of ineffective postoperative heparinisation were higher in patients with these small, abnormal echos (p < 0.05 and p < 0.001, respectively). These appearances disappear at long-term transoesophageal echocardiographic control examinations in about half the cases. The authors conclude that the majority of these small, abnormal echos are thrombotic in nature and are associated with a higher thromboembolic risk, justifying effective anticoagulation in the first postoperative hours whenever possible, considering the risk of bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)