Preoperative factors affecting the outcome of isolated mitral valve replacement: a 10 year review

Non-rheumatic-acquired valvular disease in the elderly

The analysis of the clinical data permit some conclusions about the state of the art of valvular lesions. (i) Mitral stenosis is not the predominant lesion any more, particularly above 65 years of age, although is it still more frequent in females. The decreased appearance of new cases goes parallel with the reduced incidence of rheumatic fever, showing indirectly that the latter is the most common cause of the disease. (ii) Mitral insufficiency is the fourth most common lesion, without any age- and sex-dependent differences. Ischemic heart disease, floppy mitral valve and bacterial endocarditis are the usual causes above the age of 65 years. (iii) Aortic stenosis is becoming the predominant valvular lesion, especially in females over 65 years of age; two thirds of cases have good left ventricular function, emphasizing that surgical removal of the stenotic valve in persons above 75 years may be performed more frequently. (iv) The incidence of aortic regurgitation has not changed during the last 10 years; however, rheumatic fever and syphilis are not any more the main causes, but aortic annular ecstasy and bacterial endocarditis are the most common pathologies leading to the insufficiency of the aortic valve. Taking together these facts, and considering also the problems linked to the surgical treatment (or to the possibility of mitral angioplasty), the disease of the heart valves represent major problems even today.

Prognostic significance of changes in the compliance of the pulmonary venous system after isosorbiddinitrate in patients with mitral stenosis

It is agreed that a stiff pulmonary venous bed can cause severe pulmonary hypertension. This condition can also influence the clinical and hemodynamic outcome of mitral valve replacement (MVR). This study has been aimed at assessing whether changes in the pulmonary venous compliance (PVcomp) after application of isosorbiddinitrate (ISDN) can be of prognostic value in patients 6 months after MVR. PVcomp was calculated according to the Hirakawa equation in 34 patients with isolated mitral stenosis (MS) before and after ISDN. In 19 patients (group I) there was an increase of PVcomp by more than 15% (5.3 vs. 8.1 ml/mmHg), while 15 patients (group II) showed no differences in PVcomp after ISDN, despite the significant decrease in PAP and PWP in both groups (measured with the use of Swan-Ganz thermodilution catheters). Six months after MVR a significant decrease in PAP, PWP, PVR and an increase in SVI was observed in both groups during rest. During effort (25 W), significant increases in PAP and PWP were recorded in most of patients from the group II, as opposed to group I. It is concluded that significant increase in PVcomp after ISDN in patients with MS can be a prognostic of good clinical results 6 months after MVR.

Cardiac evaluation

Over the past decade there has been a dramatic, rapid development of new imaging modalities used in the evaluation of the cardiac patient. These newer techniques are frequently complex and specialized in their application and interpretation. Nonetheless, the prevalence of cardiac disease in the United States, and the wide application of these diagnostic tests, mandate that the well-rounded clinician has a basic understanding of the utility of these diagnostic modalities. Unfortunately, the burgeoning field of cardiac imaging seems at times to overshadow our most important basic diagnostic tools, namely, the history, physical exam, chest radiograph, and electrocardiogram (ECG). This review will attempt to impart a basic understanding of the newer cardiac diagnostic tests and their utility in various disease states. Emphasis on the importance of the basic clinical exam and the precise integration of specific diagnostic tests into the cardiac evaluation will be emphasized. The article will deliver a basic review of exercise treadmill testing, echocardiography, radionuclide imaging techniques, magnetic resonance imaging, and cardiac catheterization. It is hoped that this review will impart to the noncardiologist clinician a basic understanding of the cardiovascular diagnostic techniques so that an accurate, precise, cost-effective, efficient diagnostic plan for the patient with cardiovascular disease can be developed and applied.

Determinants of survival and left ventricular performance after mitral valve replacement. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease

To determine how survival and clinical status were related to left ventricular (LV) size and systolic function after mitral valve replacement, 104 patients (48 mitral regurgitation [MR], 33 mitral stenosis [MS], and 23 MS/MR) with isolated mitral valve replacement were evaluated before and after surgery. Preoperative hemodynamic abnormalities by cardiac catheterization were improved 6 months after surgery in all three patient groups. The patients with MR exhibited reductions in LV end-diastolic volume index (EDVI) (117 +/- 51 to 89 +/- 27 ml/m2, p less than 0.001) and ejection fraction (EF) (0.56 +/- 0.15 to 0.45 +/- 0.13, p less than 0.001); however, the ratio of forward stroke volume to end-diastolic volume increased (0.32 +/- 0.21 to 0.45 +/- 0.17, p less than 0.001) because of the elimination of regurgitant volume. Survival analysis revealed that mortality was significantly higher in MS or MS/MR patients with postoperative EDVI more than 101 ml/m2 (p less than 0.001 and p less than 0.042, respectively) and in MR patients with postoperative EF less than or equal to 0.50 (p less than 0.031). Also, the majority of patients with MR or MS/MR and postoperative EDVI more than 101 ml/m2 and EF less than or equal to 0.50 were in New York Heart Association class III or IV. Multivariate logistic regression analysis in the patients with MR revealed that the strongest predictor of postoperative EF was preoperative EF (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Left atrial dimension and risk of systemic embolism in patients with a prosthetic heart valve. Department of Veterans Affairs Cooperative Study on Valvular Heart Disease

The relation between left atrial dimension measured by M-mode echocardiography and systemic embolization after valve replacement was examined prospectively among 397 patients with a prosthetic valve enrolled in the Department of Veterans Affairs Cooperative Study on Valvular Heart Disease. Baseline characteristics including several measures of left atrial enlargement were compared for 31 patients who developed systemic embolism and 366 who did not develop embolism during a 5 year follow-up period. Variables that were significantly related to left atrial dimension or systemic embolization in univariate analyses were included with several others in a multiple logistic regression model. The incidence rate of systemic embolism was more than three times higher after mitral valve replacement than after aortic valve replacement (4.4 and 1.3 per 100 patient-years, respectively); this difference persisted after adjustment for other factors. Univariate analysis indicated a threefold higher incidence of systemic embolism in patients with a left atrial dimension greater than or equal to 4 cm compared with that in patients with a dimension less than 4 cm (3 versus 1 per 100 patient-years, respectively). However, when the effect of valve location (mitral versus aortic) was taken into account using either univariate or multivariate techniques, left atrial dimension was found not to be associated with systemic embolism. In multivariate analysis, atrial fibrillation, age, ejection fraction and location of the prosthetic valve were significantly associated with embolism. Results of this multicenter study suggest that left atrial dimension is not independently related to the development of systemic embolism in patients undergoing valve replacement.

Analysis of surgical versus medical therapy in active complicated native valve infective endocarditis

From 1972 to 1980, 23 patients (Group A) with native valve infective endocarditis underwent surgical intervention, often for multiple indications, during the active stage of the infective process because of progressive class III and IV (New York Heart Association) heart failure (12 patients), persistent severe hypotension (3 patients), uncontrolled infection for over 21 days (11 patients), aortic root abscess (2 patients), and pericarditis (1 patient). Eighty-five patients (Group B) with active native valve endocarditis, matched for severity of illness, were treated medically. Two patients (9%) in Group A and 43 patients (51%) in Group B died during the hospital admission (p less than 0.001). Any difference in long-term cumulative survival rate between the 2 groups was largely due to the beneficial impact of surgical management on the hospital mortality. Of 23 patients in Group A, 11 (48%) had an entirely uncomplicated postoperative course. Long-term mortality rates in those with aortic valve endocarditis treated medically (79%) were significantly higher than in those with mitral valve involvement (47%) (p less than 0.05). Patients with aortic valve involvement treated surgically had a better hospital (p less than 0.005) and long-term (p less than 0.0005) survival rate than those treated medically. Two groups at risk for postoperative complications were identified; 3 of 11 patients (27%) with uncontrolled infection had an early postoperative recurrence, and 4 of 7 patients (57%) with an aortic root abscess had postoperative prosthetic paravalvular regurgitation. Surgery therefore effects a substantial reduction in hospital mortality in patients with complicated active infective endocarditis (9% versus 51%), but patients with preoperative prolonged periods of uncontrolled infection or with aortic root abscess are liable to postoperative complications.