Aortic valve replacement without myocardial revascularization in patients with combined aortic valvular and coronary artery disease

Challenges in Diagnosis and Functional Assessment of Coronary Artery Disease in Patients With Severe Aortic Stenosis

More than half of patients with severe aortic stenosis (AS) over 70 years old have coronary artery disease (CAD). Exertional angina is often present in AS-patients, even in the absence of significant CAD, as a result of oxygen supply/demand mismatch and exercise-induced myocardial ischemia. Moreover, persistent myocardial ischemia leads to extensive myocardial fibrosis and subsequent coronary microvascular dysfunction (CMD) which is defined as reduced coronary vasodilatory capacity below ischemic threshold. Therefore, angina, as well as noninvasive stress tests, have a low specificity and positive predictive value (PPV) for the assessment of epicardial coronary stenosis severity in AS-patients. Moreover, in symptomatic patients with severe AS exercise testing is even contraindicated. Given the limitations of noninvasive stress tests, coronary angiography remains the standard examination for determining the presence and severity of CAD in AS-patients, although angiography alone has poor accuracy in the evaluation of its functional severity. To overcome this limitation, the well-established invasive indices for the assessment of coronary stenosis severity, such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), are now in focus, especially in the contemporary era with the rapid increment of transcatheter aortic valve replacement (TAVR) for the treatment of AS-patients. TAVR induces an immediate decrease in hyperemic microcirculatory resistance and a concomitant increase in hyperemic flow velocity, whereas resting coronary hemodynamics remain unaltered. These findings suggest that FFR may underestimate coronary stenosis severity in AS-patients, whereas iFR as the non-hyperemic index is independent of the AS severity. However, because resting coronary hemodynamics do not improve immediately after TAVR, the coronary vasodilatory capacity in AS-patients treated by TAVR remain impaired, and thus the iFR may overestimate coronary stenosis severity in these patients. The optimal method for evaluating myocardial ischemia in patients with AS and co-existing CAD has not yet been fully established, and this important issue is under further investigation. This review is focused on challenges, limitations, and future perspectives in the functional assessment of coronary stenosis severity in these patients, bearing in mind the complexity of coronary physiology in the presence of this valvular heart disease.

Prevalence and Prediction of Obstructive Coronary Artery Disease in Patients Undergoing Primary Heart Valve Surgery

Background

The prevalence of coronary artery disease (CAD) in valvular patients is similar to that of the general population, with the usual association with traditional risk factors. Nevertheless, the search for obstructive CAD is more aggressive in the preoperative period of patients with valvular heart disease, resulting in the indication of invasive coronary angiography (ICA) to almost all adult patients, because it is believed that coronary artery bypass surgery should be associated with valve replacement.

Objectives

To evaluate the prevalence of obstructive CAD and factors associated with it in adult candidates for primary heart valve surgery between 2001 and 2014 at the National Institute of Cardiology (INC) and, thus, derive and validate a predictive obstructive CAD score.

Methods

Cross-sectional study evaluating 2898 patients with indication for heart surgery of any etiology. Of those, 712 patients, who had valvular heart disease and underwent ICA in the 12 months prior to surgery, were included. The P value < 0.05 was adopted as statistical significance.

Results

The prevalence of obstructive CAD was 20%. A predictive model of obstructive CAD was created from multivariate logistic regression, using the variables age, chest pain, family history of CAD, systemic arterial hypertension, diabetes mellitus, dyslipidemia, smoking, and male gender. The model showed excellent correlation and calibration (R² = 0.98), as well as excellent accuracy (ROC of 0.848; 95%CI: 0.817-0.879) and validation (ROC of 0.877; 95%CI: 0.830 - 0.923) in different valve populations.

Conclusions

Obstructive CAD can be estimated from clinical data of adult candidates for valve repair surgery, using a simple, accurate and validated score, easy to apply in clinical practice, which may contribute to changes in the preoperative strategy of acquired heart valve surgery in patients with a lower probability of obstructive disease.

The prognostic impact of concomitant coronary artery bypass grafting during aortic valve surgery: implications for revascularization in the transcatheter era

OBJECTIVE

Clinicians may give greater consideration to medical management versus coronary artery bypass grafting (CABG) for coronary artery disease (CAD) at the time of aortic valve intervention. We evaluated the prognostic impact of revascularization strategy during aortic valve replacement (AVR).

METHODS

We studied 1308 consecutive patients with significant CAD (≥50% stenosis) undergoing AVR with or with out CABG between 2001 and 2010. Late mortality and its determinants were analyzed using multivariable Cox models.

RESULTS

Patients undergoing CABG (n = 1043; 18%) had more frequent angina (50% vs 26%; P < .001), left ventricular dysfunction (22% vs 14%; P = .003), advanced (>70% stenosis) CAD (85% vs 48%; P < .001), and incidence of triple-vessel/left-main CAD (44% vs 8%; P < .001). Whereas operative mortality was comparable between patients undergoing AVR plus CABG versus isolated AVR (2.9% vs 3.0%; P = .90), 5-year (72% vs 64%) and 8-year (50% vs 39%) survival was higher following CABG (P = .007). Adjusting for older age (hazard ratio [HR], 1.28 per 5 years), female sex (HR, 1.23), peripheral vascular disease (HR, 1.71), New York Heart Association functional class III to IV (HR, 1.48), and diabetes (HR, 1.50) concomitant CABG at AVR reduced late mortality risk by more than one-third (HR, 0.62, 95% confidence interval, 0.49-0.79; P < .001). CABG continued to confer a survival advantage in patients with moderate (50%-70%) (HR, 0.62; P = .02) and severe (>70%) CAD (HR, 0.62; P = .002).

CONCLUSIONS

In patients undergoing AVR with coexistent CAD, concomitant CABG reduces risk of late death by more than one-third, without augmenting operative mortality. This survival advantage persists in moderate (50% to 70%) and severe (>70%) CAD. These findings underline the prognostic importance of revascularization in this population and should influence decisions regarding revascularization strategy in patients undergoing transcatheter valve therapy.

Management of asymptomatic aortic stenosis in patients undergoing coronary artery bypass grafting

This study compared the outcomes of combined coronary artery bypass grafting (CABG)/aortic valve replacement (AVR) and CABG alone in patients with moderate aortic stenosis and determined the possible indications for AVR at the time of CABG. Between December 1988 and January 2001, in Tenri Hospital, 41 patients with aortic stenosis underwent CABG: 26 patients underwent the combined procedure and 15 patients underwent CABG alone. The patients who underwent CABG alone were separated them into 2 groups on the basis of the results of annual echocardiography: the rapid progression group, defined by an increase of deltaP by >/=10 mmHg/year, and the slow progression group. Of the 15 patients who underwent CABG alone, the probability of survival at the end of the study in 2001 was 92% at 5 years and 74% at 10 years, and the respective event-free rates were 65% and 50%. Patients less than 70 years old and who were in the rapid progression group had a greater risk for re-operation. The study suggests that patients younger than 70 years old with risk factors for rapid progression should undergo CABG/AVR, and conversely, those older than 70 years old without the risk factors can undergo CABG only.

Prediction of coronary artery disease in patients undergoing operations for mitral valve degeneration

OBJECTIVES

We sought to develop and validate a model that estimates the risk of obstructive coronary artery disease in patients undergoing operations for mitral valve degeneration and to demonstrate its potential clinical utility.

METHODS

A total of 722 patients (67% men; age, 61 +/- 12 years) without a history of myocardial infarction, ischemic electrocardiographic changes, or angina who underwent routine coronary angiography before mitral valve prolapse operations between 1989 and 1996 were analyzed. A bootstrap-validated logistic regression model on the basis of clinical risk factors was developed to identify low-risk (< or =5%) patients. Obstructive coronary atherosclerosis was defined as 50% or more luminal narrowing in one or more major epicardial vessels, as determined by means of coronary angiography.

RESULTS

One hundred thirty-nine (19%) patients had obstructive coronary atherosclerosis. Independent predictors of coronary artery disease include age, male sex, hypertension, diabetes mellitus,and hyperlipidemia. Two hundred twenty patients were designated as low risk according to the logistic model. Of these patients, only 3 (1.3%) had single-vessel disease, and none had multivessel disease. The model showed good discrimination, with an area under the receiver-operating characteristic curve of 0.84. Cost analysis indicated that application of this model could safely eliminate 30% of coronary angiograms, corresponding to cost savings of $430,000 per 1000 patients without missing any case of high-risk coronary artery disease.

CONCLUSION

A model with standard clinical predictors can reliably estimate the prevalence of obstructive coronary atherosclerosis in patients undergoing mitral valve prolapse operations. This model can identify low-risk patients in whom routine preoperative angiography may be safely avoided.

Efficacy of the internal mammary artery in combined aortic valve replacement-coronary artery bypass grafting

BACKGROUND

While internal mammary artery (IMA) use predicts improved survival after coronary bypass grafting (CABG), it remains unknown whether patients undergoing concomitant aortic valve replacement (AVR) realize a similar benefit.

METHODS

All patients at a single teaching institution, undergoing combined AVR-CABG, which included a graft to the left anterior descending coronary artery (LAD) from 1984 to 1994 (n = 227) were examined retrospectively.

RESULTS

Patients receiving an IMA graft (yesIMA, n = 135) and patients receiving only saphenous vein grafts (nonIMA, n = 92) were not different in their presenting symptoms, or in their incidence of preoperative risk factors. The patients with IMA were more likely to be male, have a later year of operation, be younger, and have a greater body surface. Morbidity was not different between groups. IMA use did not affect 30-day mortality. Long-term actuarial survival was greater in the group with IMA (63% +/- 7% vs 42% +/- 6% at 5 years, p < 0.01). A multivariate Cox proportional hazards model demonstrated that use of an IMA graft improved survival, while recent myocardial infarction, diabetes, earlier year of operation, and lower ejection fraction diminished long-term survival. The relative risk of IMA grafting was 0.570.

CONCLUSIONS

Within the limits of a retrospective analysis, patients in a modern era of cardiac operation, who undergo combined AVR-CABG, do not suffer increased morbidity from IMA use, and may realize a survival benefit from use of the IMA as a conduit for bypass of the LAD coronary artery.

Aortic valvular replacement in octogenarians. Short-term and mid-term results in 140 patients

Aortic valvular replacements were performed between 1986 and 1995 at Rouen University Hospital on 140 octogenarians (52 male and 88 female). Pure or predominant aortic stenosis was present in 115 patients, 25 had associated aortic stenosis and insufficiency or predominant aortic insufficiency. Significant coronary lesions were present in 42% of patients. An isolated aortic valvular replacement was performed in 74% of patients, associated with a bypass in 23% and a bioprosthesis was used in 90%. Valvular lesions were mainly caused by Mönckeberg disease. Thirteen operative deaths occurred (9.3%). Functional recovery was satisfactory in 78%, mean hospital stay was 12 days. All well-known risk factors for aortic valvular replacement: age, coronary lesions, cardiac insufficiency, impaired ejection fraction and aortic insufficiency, led to an increase in operative mortality but were not statistically significant. Late mortality occurred in 28 patients, 99 patients are still alive at 4-91 months after surgery. The actuarial survival curve shows a 56.5% probability of surviving 5 years. Eighty per cent of survivors are able to live independently at home.

Use of transesophageal echocardiography to predict significant coronary artery disease in aortic stenosis

STUDY OBJECTIVES

This study was conducted to examine if the use of multiplane transesophageal echocardiography (TEE) could predict the absence or the presence of significant coronary artery disease (CAD) in patients with aortic stenosis.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Clinical, angiographic features and TEE findings were prospectively analyzed in 132 consecutive patients with aortic stenosis.

MEASUREMENTS AND RESULTS

In 63 patients with significant CAD, 57 had thoracic aortic plaque on TEE studies. In contrast, aortic plaque existed in only 19 of the remaining 69 patients with normal or mildly abnormal coronary arteries. Therefore, the presence of aortic plaque on the TEE identified significant CAD with a sensitivity of 90.5%, a specificity of 72.5%, and with positive and negative predictive values of 75.0% and 89.3%, respectively. There was a significant relation between the severity of thoracic aortic atherosclerosis and the severity of CAD (p<0.0001). Multivariate logistic regression analysis revealed that aortic plaque, angina, and age were independent predictors of CAD. Aortic plaque was the most significant independent predictor.

CONCLUSION

This prospective study indicates that TEE examination of thoracic atherosclerotic plaque is a powerful predictor of absence of significant CAD in patients with aortic stenosis.

Aortic valve replacement in patients aged eighty years and older: early and long-term results

We have studied 322 patients, 80 years of age or older, who underwent aortic valve replacement between June 1971 and December 1992. Two hundred six patients (64%) have had surgery since the end of 1985. Their mean age was 82.7 years (range 80 to 92 years). One hundred seventy-one (53%) were male and most (86%) were in New York Heart Association class III-IV. Fifty-seven patients (18%) required admission to the coronary care unit before the operation. One hundred seventy-nine patients (56%) underwent an urgent or emergency operation. Known cerebrovascular disease was present in 77 (24% of patients), aortic stenosis in 79%, aortic incompetence in 9%, and combined stenosis and incompetence in 12%. Associated procedures included bypass grafting in 139 (43%), mitral valve replacement/repair in 20 (6%), tricuspid valve repair in 6 (2%), and aortic annular enlargement in 38 (12%). Thirty patients (9.3%) were undergoing reoperation. Hospital mortality was 44 of 322 (13.7%). The median hospital stay was 11 days. On univariate analysis, significant predictors of hospital mortality were female sex, preoperative rest pain, New York Heart Association class III-IV, admission to the coronary care unit, heart failure, mitral valve disease, emergency/urgent operation, chronic obstructive pulmonary disease, bypass grafting, valve size, peripheral vascular disease, and ejection fraction less than 0.35. On multivariate analysis the most important independent predictors of operative mortality were female gender (p = 0.0001), renal impairment (p = 0.001), bypass grafting (p = 0.005), ejection fraction less than 0.35 (p = 0.01), and chronic obstructive pulmonary disease (p = 0.028). Age and year of operation did not influence mortality. Five-year survivals for all patients and for operative survivors were 60.2% +/- 3.2% and 70.3% +/- 3.4%, respectively. On univariate analysis, factors that adversely affected long-term survival were coronary bypass grafting (p = 0.007), more than two comorbidities (p = 0.02), male gender (p = 0.04), and ejection fraction less than 0.35 (p = 0.04). On multivariate analysis, no factor was consistently significant for long-term survival. At most recent clinical follow-up 85% were angina free and 82% were in class I-II. At least 92% of patients, both at 1 year and at most recent clinical follow-up, believed they had significantly benefited from the operation:

CONCLUSION

Risk factors for aortic valve replacement in octogenarians include female gender, unstable symptoms, poor ejection fraction, renal impairment, and bypass grafting. However, despite a hospital mortality higher than that reported for younger patients, the outlook for operative survivors is excellent, with good relief of symptoms and an expected survival normal for this particular age group. If possible, aortic valve replacement should be done before development of unstable symptoms.

The influence of coronary artery disease and bypass grafting on early and late survival after valve replacement for aortic stenosis

The influence of coronary artery disease and bypass grafting on survival after valve replacement for aortic stenosis (1975 to 1986, N = 512) was analyzed. Mean follow-up for 30-day survivors was 5.1 years (0.1 to 12.9 years). A total of 205 patients had coronary angiography performed: 122 did not have coronary artery disease, 55 with coronary artery disease underwent bypass grafting, and 28 with coronary artery disease did not. Early mortality rates (less than or equal to 30 days)/5-year cumulative survivals (standard error) were 4.1%/86% (4%), 3.6%/68% (8%), and 17.9%/51% (13%), respectively (p less than 0.05/p less than 0.01). Triple vessel/left main stem disease was more prevalent in patients with coronary disease who underwent bypass grafting (47%) than in those who did not (14%; p less than 0.05). Multivariate analysis revealed that right ventricular failure and omission of bypass grafting in patients with coronary artery disease were independent determinants of early mortality. A Cox regression analysis identified coronary artery disease and aortic valve gradient as determinants of mortality after hospital dismissal, which was not influenced by bypass grafting. On the basis of a coronary artery disease score (positive predictive value for coronary artery disease of 66%) developed on the patients with angiography, 307 patients without angiography were divided into 234 with a low score and 73 with a high score. Early mortality rates/5-year survivals (standard error) were 6.4%/86% (2%) and 16.4%/67% (6%), respectively (p less than 0.01/p less than 0.001). Autopsy revealed stenotic or occlusive coronary artery disease in 92% of 12 early deaths in the group with a high coronary artery disease score and in 33% of 15 in the group with a low score (p less than 0.01). Left ventricular failure and a high coronary artery disease score were independent determinants of early mortality, whereas cardiothoracic index, a high coronary artery disease score, and left ventricular failure were independent predictors of death after hospital dismissal. Despite more severe coronary artery disease, bypass grafting reduced early mortality to a level comparable with that of patients without coronary artery disease, contrasting with a high early mortality rate for unbypassed coronary artery disease. Coronary artery disease increased the late mortality rate, which was not modified by bypass grafting. In the group without angiography, undiagnosed and unbypassed coronary artery disease probably increased both early and late mortality. Coronary angiography should be performed in all adult patients with aortic stenosis, and those with significant coronary artery disease should undergo bypass grafting concomitant with valve replacement.

Indications for heart valve replacement

Proper evaluation of the patient with valvular heart disease begins with a thorough history and physical examination. Today, sophisticated noninvasive tests--especially echocardiography with color flow Doppler imaging--complement the information gained at cardiac catheterization. Information previously available only through cardiac catheterization can now be obtained from these noninvasive techniques. Serial evaluations can be performed, which are important in managing lesions of borderline hemodynamic significance and in avoiding subclinical deterioration of left ventricular contractility. Improvements in surgical expertise and intraoperative myocardial preservation allow postoperative improvement for patients with aortic stenosis and aortic insufficiency despite the presence of left ventricular systolic dysfunction. Many traditional indicators of a poor operative result in aortic insufficiency appear less reliable today. Consequently, these indicators should never be viewed in isolation or be given preeminence over clinical judgment. The long-term results following aortic valvuloplasty have been disappointing. However, mitral valvuloplasty--for technically suitable types of mitral stenosis--is an attractive alternative to surgery. Echocardiography may be helpful in selecting patients best suited for this technique. The timing of valve replacement in mitral insufficiency is made difficult by the altered loading conditions which can mask underlying contractile dysfunction. In this regard, the use of end-systolic measurements (e.g., end-systolic stress-volume ratio) more accurately characterized left ventricular contractility. When mitral insufficiency patients with left ventricular systolic dysfunction require surgery, valve repair appears superior to traditional mitral valve replacement. With valve repair, the postoperative left ventricular ejection fraction is usually higher, as left ventricular contractile reserve is better maintained.

Clinical and ultrasound results after aortic valve replacement: intermediate-term follow-up with the St. Jude Medical prosthesis

Mortality, morbidity, quality of life, and left ventricular (LV) function were evaluated in 49 patients after aortic valve replacement with the St. Jude prosthesis. Total follow-up was 2577 patient-months; survivors were followed-up for 4 to 7 years by clinical examination and echocardiography. The actuarial survival rate at 6 years was 79.6%, and there were no valve-related deaths. The linearized rates for thromboembolism and hemorrhage were 0.93% and 3.26% per patient-year, respectively. In 34% of the survivors the quality of life was poor. In the first three postoperative months, patients with aortic stenosis (n = 12) had a significant decrease in the muscle cross-sectional area (p less than 0.01) and patients with aortic regurgitation (n = 11) had decreases in both LV end-diastolic diameter (p less than 0.05) and cross-sectional area (p less than 0.001). All of these results were maintained at 5 years without modification of LV systolic function. Despite the good overall results, six patients deteriorated and had major LV dilatation. Multivariate logistic regression analysis identified two independent preoperative variables associated with a poor outcome defined as death of LV dysfunction (p less than 0.05): age and end-diastolic diameter. Thus meticulous follow-up showed a high incidence of hemorrhage and a poor quality of life in many of the survivors. It was concluded that in high-risk patients (age and end-diastolic diameter) surgery should probably be considered earlier.

Aortic valve replacement with combined myocardial revascularisation

Early and late outcome was studied in 630 patients who underwent aortic valve replacement between 1974 and 1982. Group 1 (506 patients) did not have important coronary artery disease, group 2 (69 patients) had coronary artery disease and underwent coronary artery bypass grafting, and group 3 (55 patients) had coronary artery disease but did not undergo myocardial revascularisation. Early mortality (within 30 days of operation) was significantly lower for group 1 (6%) than for group 2 (13%) and for group 3 (16%). Operative mortality in all three groups was lower in patients operated on more recently. The three year survival of patients in group 1 (83%) was significantly higher than that of patients in group 3 (62%) but not than that of patients in group 2 (76%). The findings of this study suggest that the presence of coronary artery disease increases the risk of aortic valve replacement whether or not coronary artery grafting is performed. Myocardial revascularisation, however, seems to return patients with aortic valve and coronary artery disease to a survival curve similar to that of patients with isolated aortic valve disease.

Coronary artery disease and its management: influence on survival in patients undergoing aortic valve replacement

Data from 1,156 patients greater than or equal to 30 years of age who underwent aortic valve replacement alone or with coronary artery bypass grafting from 1967 through 1976 (early series) and 227 similar patients operated on during 1982 and 1983 (late series) were reviewed. In the early series, 414 patients (36%) had preoperative coronary arteriography (group 1): group 1A (n = 224) did not have coronary artery disease, group 1B (n = 78) had coronary artery disease but did not undergo bypass grafting and group 1C (n = 112) had coronary artery disease and underwent bypass grafting. The 742 patients in group 2 did not have preoperative arteriography. Operative mortality rates (30 day) in groups 1A, 1B, 1C and 2 were 4.5, 10.3, 6.3 and 6.3%, respectively (p = NS). The 10 year survival in both groups 1 and 2 was 54%; in groups 1A, 1B and 1C it was 63, 36 and 49%, respectively (1A and 1B, p less than 0.01). In the late series, the 227 patients were divided into similar groups (group 1A, n = 73; 1B, n = 32; 1C, n = 99), and 90% had preoperative coronary arteriography. Operative mortality rates (30 day) for groups 1A, 1B and 1C were 1.4, 9.4 and 4.0%, respectively; that for group 2 (no preoperative arteriography, n = 23) was 4.3%. Definition of coronary anatomy by angiography seems important in most patients greater than or equal to 50 years old who are candidates for aortic valve replacement, and bypass grafting is recommended for those with significant coronary artery disease.

Prognostic significance of exercise-induced left ventricular dysfunction in chronic aortic regurgitation

Twenty-three patients with hemodynamically significant aortic regurgitation (AR) underwent gated equilibrium radionuclide angiography to assess rest and exercise left ventricular ejection fraction (LVEF) before and after aortic valve replacement. Preoperatively, LVEF decreased from 54 +/- 3% at rest to 45 +/- 3% during exercise (p less than 0.001). Two patients died at operation. Postoperatively, after 5.7 +/- 1.6 months, LVEF was 62 +/- 5% at rest and 60 +/- 4% during exercise (difference not significant). Exercise LVEF improved significantly postoperatively (p less than 0.01). The patients were followed for a mean of 30 months (range 1 to 56), after valve replacement and during this period, 13 patients were in functional class I, 5 patients were in class II and 2 patients were in class III. One late death occurred and was unrelated to myocardial failure. Thus, in most patients with AR, exercise LVEF improves after aortic valve replacement. A preoperative decrease in LVEF during exercise in patients with significant AR does not predict a poor postoperative outcome.

Late results of combined mitral valve replacement and coronary bypass surgery

The incremental risk of coronary bypass surgery was analyzed in 718 patients undergoing mitral valve replacement between 1971 and 1983. Ninety-eight patients (14%) had significant coronary artery disease requiring coronary bypass surgery. In 70 of these patients, the origin of the mitral valve disease was nonischemic, whereas 28 patients had ischemic mitral regurgitation unsuitable for conservative valve surgery. There were six operative deaths (9%) and four perioperative myocardial infarctions (6%) after mitral valve replacement and coronary bypass surgery for nonischemic mitral valve disease. Operative mortality was related to low output cardiac failure before operation or perioperative myocardial infarction. Actuarial curves predict survival (+/- standard error) of 55 +/- 7% at 5 years and 43 +/- 8% at 10 years. Preoperative functional class was the only significant predictor of long-term survival in this group (p less than 0.05). The actuarial survival of the 620 patients without coronary artery disease who underwent mitral valve replacement alone was 63 +/- 3% at 10 years. This was significantly better than that of the 70 patients who underwent mitral valve replacement and coronary bypass surgery for nonischemic mitral valve disease (p less than 0.001). Conversely, 5 year survival of the 28 patients with ischemic mitral regurgitation was 43 +/- 10%. This confirms the negative detrimental effect of an ischemic origin of mitral valve disease on survival after mitral valve replacement and coronary bypass surgery (p less than 0.0001).

Cardiovascular disease and work place exposures

The typical occupational cohort study includes all causes of mortality. However, emphasis is usually placed on the presence or absence of excess cancer mortality. A systematic review of completed occupational cohort studies to assess the findings and patterns of cardiovascular mortality would be useful. Although many of these studies will illustrate the "healthy worker effect" with deficits in mortality, particularly from cardiovascular causes, a thorough review should indicate certain exposures needing further research. A recently published study of heart disease mortality in the rubber industry illustrates the potential use of such a literature review with subsequent follow up. Production workers in the rubber industry have shown small excesses in CAHD mortality. A follow-up study at one plant confirmed the known association between carbon disulfide and atherosclerosis, as well as suggested two new causal associations between CAHD and the use of phenol and ethanol as solvents. What additional techniques can be used to generate hypotheses on heart disease and occupation? Some possibilities include: A recent article describes the use of the results of occupational disease surveillance systems for occupational cancer research. A review of such systems for heart disease would be equally useful. It would be useful to review the quality and quantity of occupational data that has been collected in prospective cohort studies, such as those in Framingham and Evans County. The importance of examining the association between occupational exposures and heart disease include: Assessing whether adequate protection is afforded by current limits on exposure to substances known to cause heart disease (carbon disulfide, nitrates, and carbon monoxide).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaphylactoid reaction to angiographic contrast media: recurrence despite pretreatment with corticosteroids

A case who developed severe and potentially fatal reaction to an angiographic contrast medium despite adequate pretreatment with steroids for 2 weeks is reported. This is the second such case reported in the English literature.

Replacement of aortic valve combined with myocardial revascularization: determinants of early and late risk for 500 patients, 1967-1981

Five hundred consecutive patients underwent aortic valve replacement and coronary revascularization in the years from 1967 to 1981, with 29 (5.9%) in-hospital deaths. Current operative mortality (1978-1981) is 3.4%. Univariate and multivariate analyses were used to identify determinants of early and late risk. Female sex, aortic insufficiency, and advanced age increased in-hospital mortality, whereas use of cardioplegia decreased it. At follow-up of 471 patients who survived hospitalization for 1 to 135 months (mean 41) after surgery, 96 late deaths were documented. Survival rates were 87%, 80%, and 55%, and event-free survival rates were 80%, 65%, and 39% at 2, 5, and 10 years after surgery, respectively. The late survival rate was unfavorably influenced by the presence of moderately or severely impaired left ventricular function and double-vessel coronary disease; the rate was enhanced for patients in age group from 50 to 59 years old and was not influenced by the method of myocardial protection. The event-free survival rate decreased with the presence of moderately or severely impaired left ventricular function and was enhanced for patients with New York Heart Association class I or II symptoms before surgery. Patients with bioprostheses who did not receive anticoagulants had higher survival and event-free survival rates than did either patients with bioprostheses who received anticoagulants or patients with mechanical valves, whether they received anticoagulants or not.

Noninvasive assessment of valvular heart disease: surgery without catheterization

Forty-one patients underwent valve surgery at our institution based solely on clinical, M-mode echocardiographic, phonocardiographic, and external pulse recording findings without preoperative cardiac catheterization. Patients with clinical evidence of coronary artery disease were excluded from the study. Preoperatively, 83% of the patients were New York Heart Association functional class III or IV. In all patients, the noninvasive evaluation was considered sufficiently diagnostic of the nature and severity of valvular heart disease to allow surgery without preoperative catheterization. In 23 of 41 cases (group 1), cardiac catheterization was not performed due to the patients' unstable hemodynamic condition at the time surgery was being considered. In the remaining 18 patients (group 2), the probability of obtaining data at catheterization that would significantly affect management decisions was thought to be low, thus not justifying the cost and potential morbidity of this procedure. In all cases, the noninvasive diagnosis was corroborated at operation; there were no unexpected findings nor deaths related to incomplete or incorrect diagnoses. Over a followup period of 4.5 +/- 1.4 years, no patient experienced signs or symptoms of ischemic heart disease. In selected patients without anginal chest pain syndromes, appropriate and successful valve surgery may be performed on the basis of combined clinical and noninvasive evaluation without the need for cardiac catheterization.

Combined aortic valve replacement and myocardial revascularization. Experience with a cold cardioplegic technique

The authors reviewed their experience with combined aortic valve replacement and coronary artery bypass grafting using a standardized cold cardioplegic technique for intraoperative myocardial protection in 54 consecutive patients during a 5-year interval ending in May 1982. Calcific aortic stenosis was the most common indication for aortic valve replacement. Thirty-seven patients (69%) had greater than 50-60% stenoses in at least two of the three major coronary arterial systems. No patient with combined aortic valvular and coronary artery disease had only valve replacement during the study interval, and no patient was refused operation. The mean number of arteries grafted was 2.4. There was one hospital death (1.9%), and one patient (1.9%) had electrocardiographic evidence for perioperative myocardial infarction. One additional patient required postoperative intra-aortic balloon pumping. There have been four late deaths in the followup period extending to 65 months. Survival at 3 years for the entire group was 87%, for the patients with aortic stenosis was 95%, and for the patients with aortic regurgitation or mixed lesions was 65%. There were no cardiac-related deaths among the patients with aortic stenosis and one non-fatal myocardial infarction in the follow-up period. The results with this technique of intraoperative myocardial protection are superior to those reported with previously employed methods (coronary perfusion, hypothermic ischemic arrest) and indicate that coronary artery bypass grafting should be performed in all patients with coexisting aortic valvular and coronary artery disease who require valve replacement. A substantial benefit (increased survival, decreased late myocardial infarction) may exist for the subgroup of patients with aortic stenosis.

Aortic valve replacement and coronary bypass in patients with severe stenosis of the left main coronary artery

Adequate myocardial protection is difficult to achieve during operations for combined aortic valve disease and severe stenosis of the left main coronary artery. A double cross-clamp technique, which facilitates the delivery of cardioplegic solution to the myocardium, is described here. We reviewed the experiences of 11 patients, 6 of whom underwent operation using the new technique.

Valvular heart disease: a perspective

Valve replacement has been one of the most important advances in the management of patients with valvular heart disease. The 10 and 15 year survival rate after isolated aortic and mitral valve replacement with the Starr-Edwards valve is 56 and 44%, respectively. At 5 and 7 years, survival with the Björk-Shiley, porcine bioprosthesis and the Starr-Edwards valve is similar. Patients operated on during the last 5 to 10 years have a much better survival rate than those operated on in the 1960s; therefore, the 10 and 15 year survival of those operated on recently should improve. All patients with a mechanical prosthesis need long-term anticoagulant therapy with drugs of the coumadin type. Porcine bioprostheses have a low failure rate up to 5 years after valve replacement; after this, valve failure occurs at an increasing rate, but the incidence at 10 and 15 years is not known. Valve replacement usually produces a marked improvement in the symptomatic status of the patient because of improved hemodynamics; ventricular function is improved in selected subsets of patients. The role of long-term vasodilator therapy has not been fully determined. Antibiotic prophylaxis for secondary prevention of rheumatic carditis and for prevention of infective endocarditis is important.

Echocardiography in chronic aortic insufficiency. Is valve replacement too late when left ventricular end-systolic dimension reaches 55 mm?

To determine whether a ventricular (LV) end-systolic dimension (ESD) greater than or equal to 55 mm and LV left fractional shortening less than 25% are risk factors for aortic valve replacement (AVR) in patients with aortic insufficiency, we analyzed the clinical course and M-mode echocardiograms in 47 consecutive patients who underwent AVR for isolated symptomatic AI. Group 1 patients (n = 27) had a preoperative ESD less than 55 mm (mean 44 mm, range 30-52 mm) and group 2 patients (n = 20) had a preoperative ESD greater than or equal to 55 mm (mean 62 mm, range 55-85 mm). One patient in group 1 and 10 patients in group 2 had left ventricular fractional shortening less than 25%. There were no perioperative or postoperative deaths during an average follow-up of 41 months (range 6-76 months). Five patients had perioperative myocardial infarctions (MIs), three in group 1 and two in group 2. Since myocardial protection with cold potassium cardioplegia was instituted, no patient has suffered a perioperative MI. The average preoperative New York Heart Association functional classification was 2.3 (group 1) and 2.6 (group 2). Postoperatively, it was 1.2 in group 1 and 1.1 in group 2. Thirty-three patients (20 in group 1 and 13 in group 2) had echocardiograms at least 1 year after AVR. Of these, LV-end diastolic dimension decreased fro 67 +/- 6 to 53 +/- 6 mm (mean +/- SD) in group 1 (p less than 0.001) and from 79 +/- 3 to 55 +/- 6 mm in group 2 (p less than 0.001). The LVESD also decreased, but this is difficult to interpret because of frequent postoperative abnormal interventricular septal motion. The LV cross-sectional area, an index of LV mass, decreased in group 1 from 25 +/- 5 to 20 +/- 5 cm2 (p lss than 0.001) and in group 2 from 32 +/- 9 to 20 +/- 5 cm2 (p less than 0.001). Postoperative end-diastolic dimension and cross-sectional area were not significantly different between the two groups. We concluded that in aortic insufficiency, a preoperative ESD greater than or equal to 55 mm does not preclude successful AVR, as judged by long-term survival, symptomatic relief, and normalization of LV dimensions assessed by echocardiography.

Is cardiac catheterisation necessary before valvular surgery?

The results of 269 patients who had undergone valvular operations during and 18-month period (January 1, 1980, to June 30, 1981) were analysed. One hundred and seventy-four patients referred for surgery had undergone routine cardiac catheterisation elsewhere, and these, together with four electively catheterised patients, constituted a group representing the conventional approach. Ninety-one patients were assessed only by clinical and non-invasive methods, including echocardiography, and were subjected to surgery without catheterisation. The two groups were comparable in their major clinical characteristics including age, sex ratio, functional class, previous history of closed mitral valvotomy, aetiology of valve lesions, and type of operative procedure performed. There was no discordance between operative finding and preoperative assessment, except in two patients of the catheterised group. Hospital mortality was acceptably low and was comparable between the two groups. Cardiac catheterisation is, thus, no longer necessary in the majority of patients undergoing surgery for valvular heart diseases.

Valve replacement without preoperative cardiac catheterization

During the year 1978, the decision to perform cardiac catheterization in patients with valvular heart disease was delayed until clinical and noninvasive assessment have been completed. As a result, 184 patient underwent operation without invasive studies, and 59 had elective catheterization. Another 62 patients were referred during the same period for valve replacement after routine catheterization had been performed elsewhere. Age, sex distribution, symptoms, and cause of valve disease were similar in all three groups, although we managed emergencies and second operations more frequently without catheterization. In all patients, the preoperative diagnosis was confirmed, and no unexpected pathologic process was encountered. Operative mortality was the same in all three groups, and after two years of follow-up there was no difference in survival or symptoms. No uncorrected valve lesions became apparent in uncatheterized patients. We conclude that routine catheterization is unnecessary before valve replacement but can be reserved for specific indications in some patients.