Schaff, Hartzell V.

Mini‐AbstractWe present a case of a 25‐year‐old man with aortic regurgitation secondary to infective endocarditis. A preoperative transesophageal echocardiography demonstrated an abnormal aortic valve with possible vegetation or torn leaflet with severe aortic regurgitation, markedly dilated left coronary arteries, and a fistulous communication between the circumflex artery and the coronary sinus. The aortic valve was repaired and the coronary sinus arteriovenous fistula was ligated. At 1‐year follow‐up, there was no evidence of recurrent arteriovenous fistula or aortic regurgitation.

Background— Use of the left internal mammary artery (LIMA) in multivessel coronary artery disease improves survival after coronary artery bypass graft surgery; however, the survival benefit of multiple arterial (MultArt) grafts is debated. Methods and Results— We reviewed 8622 Mayo Clinic patients who had isolated primary coronary artery bypass graft surgery for multivessel coronary artery disease from 1993 to 2009. Patients were stratified by number of arterial grafts into the LIMA plus saphenous veins (LIMA/SV) group (n=7435) or the MultArt group (n=1187). Propensity score analysis matched 1153 patients. Operative mortality was 0.8% (n=10) in the MultArt and 2.1% (n=154) in the LIMA/SV ( P =0.005) group, which was not statistically different ( P =0.996) in multivariate analysis or the propensity-matched analysis ( P =0.818). Late survival was greater for MultArt versus LIMA/SV (10- and 15-year survival rates were 84% and 71% versus 61% and 36%, respectively [ P <0.001], in unmatched groups and 83% and 70% versus 80% and 60%, respectively [ P =0.0025], in matched groups). MultArt subgroups with bilateral internal mammary artery/SV (n=589) and bilateral internal mammary artery only (n=271) had improved 15-year survival (86% and 76%; 82% and 75% at 10 and 15 years [ P <0.001]), and patients with bilateral internal mammary artery/radial artery (n=147) and LIMA/radial artery (n=169) had greater 10-year survival (84% and 78%; P <0.001) versus LIMA/SV. In multivariate analysis, MultArt grafts remained a strong independent predictor of survival (hazard ratio, 0.79; 95% confidence interval, 0.66–0.94; P =0.007). Conclusions— In patients undergoing isolated coronary artery bypass graft surgery with LIMA to left anterior descending artery, arterial grafting of the non–left anterior descending vessels conferred a survival advantage at 15 years compared with SV grafting. It is still unproven whether these results apply to higher-risk subgroups of patients.

Experiments were designed to determine whether endothelial injury contributes to augmented coronary vascular tone seen during myocardial reperfusion. Canine left anterior descending coronary arteries were exposed to ischemia followed by reperfusion (60 minutes each). Rings (3-4 mm) of the reperfused artery and of normal left circumflex (control) coronary artery segments were prepared. Rings were suspended for isometric force measurement in organ chambers containing modified Krebs' Ringer bicarbonate solution (37 degrees C, 95% O2-5% CO2). Endothelium-independent contractions to KCl and prostaglandin F2 alpha were unaltered after reperfusion. Endothelium-dependent relaxations to nitric oxide, sodium nitroprusside, and isoproterenol were comparable in control and reperfused arteries. However, reperfused coronary arteries contracted with prostaglandin F2 alpha lost the ability to express endothelium-dependent relaxations to aggregating platelets. Reperfused arterial rings also exhibited impaired endothelium-dependent relaxations to acetylcholine, the calcium ionophore A23187, and the platelet-derived compounds ADP and serotonin. Quiescent (noncontracted) reperfused arterial rings exhibited larger contractions than controls when exposed to aggregating platelets. In such quiescent rings, the endothelium-dependent increase in tension to hemoglobin was unaltered after reperfusion. Thus, coronary reperfusion impairs the normal endothelium-dependent relaxations to aggregating platelets and vasoactive drugs. This impairment of platelet-mediated coronary relaxation could help explain the increased vascular tone and tendency toward vasospasm commonly observed after reperfusion of the coronary arteries.

Background —The objectives of our study were to determine the frequency of supraventricular tachyarrhythmias (SVTAs) among modifications of the Fontan operation and identify risk factors for developing SVTA. Methods and Results —The population consisted of all patients who had any modification of the Fontan operation at the Mayo Clinic between 1985 and 1993. Clinically significant SVTAs were those requiring initiation or change of antiarrhythmic treatment, and they were divided into early SVTAs (<30 days after the operation) and late SVTAs (≥30 days after the operation). Clinical histories were reviewed, and health status questionnaires were sent. Four hundred ninety-nine patients had various modifications of the Fontan operation. Frequency of early SVTA was 15%. Risk factors identified by multivariate analysis for early SVTA were AV valve regurgitation, abnormal AV valve, and preoperative SVTA. Frequency of late SVTA was 6% by 1 year, 12% by 3 years, and 17% by 5 years. Risk factors for late SVTA were age at operation (<3 or ≥10 years) and systemic AV valve replacement. By univariate and multivariate analysis, the type of Fontan operation was not a significant risk factor for late SVTA when all 6 modifications were considered. However, when we analyzed the frequency of late SVTA for the 2 recently used modifications, we found a lower frequency of late SVTA in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection. Conclusions —Postoperative SVTA continues to be a significant problem. Risk factors for SVTA are AV valve regurgitation, abnormal AV valve, preoperative SVTA, and age at operation. Frequency of SVTA does not appear to be related to type of Fontan procedure except for slightly lower frequency in patients with atriopulmonary connection with lateral tunnel compared with those with total cavopulmonary connection.

Background The optimal timing for surgery in patients with mitral regurgitation is disputed. Because of the frequency of left ventricular dysfunction, which is difficult to predict, early surgery has been recommended, but its potential benefits have not been demonstrated. Methods and Results The outcomes of 221 patients (mean age, 65±13 years; 71% males) with flail leaflets diagnosed with two-dimensional echocardiography between 1980 and 1989 who were eligible for operation were analyzed. Group I comprised 63 patients who had early mitral valve surgery (within 1 month after diagnosis). Group II comprised 158 patients initially treated conservatively (80 of whom were operated on later). Group I patients were younger ( P =.009), had more symptoms ( P <.0001), and were more frequently in atrial fibrillation ( P =.023) than group II patients. There was no difference in ejection fraction between the groups. The early surgery strategy was followed by an improved overall survival rate ( P= .028) and a lower incidence of cardiovascular deaths ( P =.025), congestive heart failure ( P =.046), and new chronic atrial fibrillation ( P =.032), as confirmed by multivariate analysis (adjusted risk ratios of 0.31, 0.18, 0.38, and 0.05, respectively; all P< .02). Conclusions In patients with mitral regurgitation due to flail leaflets, the strategy of early surgery versus conservative management is associated with an improved long-term survival rate, decreased cardiac mortality, and decreased morbidity after diagnosis. This outcome advantage suggests that early surgery is a reasonable treatment option to be considered in low-risk candidates with repairable valves and severe mitral regurgitation.

BackgroundA subgroup of patients with hypertrophic obstructive cardiomyopathy remain severely symptomatic despite optimal medical therapy. Septal myectomy reduces or eliminates left ventricular outflow obstruction and produces marked symptomatic improvement. With the recent advent of alternative methods for treatment of this disorder, such as dual-chamber pacing, it is necessary to establish the risks and benefits of septal myectomy in the modern surgical era.Methods and ResultsThe clinical, ECG, echocardiographic, cardiac catheterization, and surgical data were analyzed for 65 patients 20 to 70 years old with hypertrophic obstructive cardiomyopathy who had surgical treatment between 1986 and 1992. Specific symptoms and overall functional status were evaluated before surgery and at the end of the first postoperative year. Subsequent long-term clinical postoperative follow-up was also obtained. The extent of postoperative improvement was measured by the presence and severity of persistent symptoms, overall New York Heart Association (NYHA) functional class, and patients' self-perceptions of overall improvement. Of the patients, 95% were in NYHA functional class III or IV before surgery: 95% had dyspnea, 62% had angina, 63% had near-syncope, and 23% had syncope. The overall early mortality rate was 4.6%; there was no mortality among the 45 patients who underwent isolated septal myectomy. At the 1-year postoperative evaluation, 89% of survivors were in NYHA functional class I or II, and 47% believed that they had 100% improvement. Significant improvement (as defined) was seen in 67% of patients with dyspnea, 90% with angina, 86% with near-syncope, and 100% with syncope. The 5-year survival rate was 92%.ConclusionsThe results of the present study reaffirm the efficacy of surgical treatment of hypertrophic obstructive cardiomyopathy in patients who are severely symptomatic despite optimal medical therapy and serve as a useful reference by which the surgical approach can be compared with new and potentially promising treatment alternatives.

Background In patients with mitral regurgitation, surgical intervention produces immediate improvement in symptoms, but the long-term incidence and significance of postoperative congestive heart failure are unknown. Methods and Results The long-term outcome of 576 operative survivors of surgical correction of pure mitral regurgitation performed between 1980 and 1989 was analyzed. Survival was 77±2% and 56±3% at 5 and 10 years, respectively. Cumulative incidence of congestive heart failure was 23±2%, 33±3%, and 37±3% at 5, 10, and 14 years, respectively. Survival after the first episode of congestive heart failure was dismal, 44±4% at 5 years. Cause of congestive heart failure was left ventricular dysfunction in two thirds of the patients and valvular dysfunction in the other third. With multivariate analysis, the independent predictors of postoperative heart failure were preoperative ejection fraction ( P =.0001), coronary artery disease ( P =.0017), and New York Heart Association functional class ( P =.012), with borderline value for atrial fibrillation ( P =.10). The performance of valve repair was independently predictive of a lower incidence of the combined end point of death and heart failure ( P =.001), compared with valve replacement. Conclusions Congestive heart failure frequently occurs late after surgical correction of mitral regurgitation and portends dismal prognosis. This complication is due most often to left ventricular dysfunction; its main determinant is decreased left ventricular function preoperatively. These data should lead to earlier indication of surgical correction of mitral regurgitation, before left ventricular dysfunction occurs.

Background We hypothesized that a simple, unmeasured posterior annuloplasty technique (two thirds of a 27-mm Duran ring) offered advantages of standardization and ease of insertion. Methods and Results A consecutive series of all patients (n=418; median age, 67 years) having mitral valve repair performed by two surgeons was analyzed to determine the outcome of three different annuloplasty techniques: commissural annuloplasty (n=124), complete ring annuloplasty (n=113), and an unmeasured, posterior, partial ring annuloplasty (n=181). Intraoperatively, before repair, severity of mitral regurgitation as measured by double sampling dye curves and transesophageal echocardiography was similar in all three groups; after mitral valve repair, intraoperative assessment showed a similar degree of reduction in regurgitation in the three annuloplasty groups. Before hospital dismissal, transthoracic echocardiography demonstrated that the mean mitral valve areas and gradients were similar in the three groups; more patients having commissural annuloplasty were classified as having grade II or greater regurgitation. Mortality (n=7, 1.7%) and need for reoperation (n=8, 1.9%) was low in all groups despite the fact that additional procedures were performed in 48.8% of patients. Durations of cardiopulmonary bypass and aortic cross-clamping were significantly less in patients having commissural or posterior annuloplasties compared with those receiving a complete ring annuloplasty. Conclusions These early results indicate that the posterior annuloplasty method is reproducible and expeditious. Postoperative valve function as assessed by degree of regurgitation, transvalvular gradient, and valve area was similar to that obtained by measured, complete ring annuloplasty and superior to that found in patients having commissural annuloplasty.

Background Aprotinin is a serine protease inhibitor that reduces blood loss and transfusion requirements when administered prophylactically to cardiac surgical patients. To examine the safety and dose-related efficacy of aprotinin, a prospective, multicenter, placebo-controlled trial was conducted in patients undergoing repeat coronary artery bypass graft (CABG) surgery. Methods and Results Two hundred eighty-seven patients were randomly assigned to receive either high-dose aprotinin, low-dose aprotinin, pump-prime-only aprotinin, or placebo. Drug efficacy was determined by the reduction in donor-blood transfusion up to postoperative day 12 and in postoperative thoracic-drainage volume. The percentage of patients requiring donor–red-blood-cell (RBC) transfusions in the high- and low-dose aprotinin groups was reduced compared with the pump-prime-only and placebo groups (high-dose aprotinin, 54%; low-dose aprotinin, 46%; pump-prime only, 72%; and placebo, 75%; overall P =.001). The number of units of donor RBCs transfused was significantly lower in the aprotinin-treated patients compared with placebo (high-dose aprotinin, 1.6±0.2 U; low-dose aprotinin, 1.6±0.3 U; pump-prime-only, 2.5±0.3 U; and placebo, 3.4±0.5 U; P =.0001). There was also a significant difference in total blood-product exposures among treatment groups (high-dose aprotinin, 2.2±0.4 U; low-dose aprotinin, 3.4±0.9 U; pump-prime-only, 5.1±0.9 U; placebo, 10.3±1.4 U). There were no differences among treatment groups for the incidence of perioperative myocardial infarction (MI). Conclusions This study demonstrates that high- and low-dose aprotinin significantly reduces the requirement for donor-blood transfusion in repeat CABG patients without increasing the risk for perioperative MI.

Background Combined severe proximal left anterior descending and proximal left circumflex coronary artery disease, or left main equivalent (LMEQ) disease, defines a prognostic high-risk angiographic subset of patients with chronic ischemic heart disease. While numerous observational and randomized clinical trials showed prolonged survival in surgically compared with medically treated patients with left main coronary artery disease, relatively few observational studies compared surgical and medical therapies in patients with LMEQ disease. The present report of 912 patients with LMEQ disease in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMEQ patient subgroups. Methods and Results The CASS Registry contains 912 patients with LMEQ disease, defined as combined stenoses of ≥70% in the proximal left anterior descending coronary artery before the first septal perforator and proximal circumflex coronary artery before the first obtuse marginal branch, initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 44% for the 630 patients in the surgical group and 31% for the 282 patients in the medical group. Median survival in the surgical group was 13.1 years (12.7 to 14.1 years, 95% confidence limits) compared with only 6.2 years (4.8 to 7.9 years) in the medical group (difference, 6.9 years; P <.0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, and coronary anatomy. However, coronary artery bypass graft (CABG) surgery did not significantly prolong median survival in patient subgroups with (1) normal LV systolic function, even if a significant right coronary artery stenosis (≥70%) also was present, and (2) mildly abnormal (LV score, 6 to 10) LV systolic function. The 15-year cumulative survival in patients with normal LV systolic function in the surgical and medical groups was 63% and 54%, respectively. Median survival was >15 years in both the surgical and medical groups ( P =NS). In patients with normal LV systolic function and right coronary artery stenosis ≥70%, the 15-year cumulative survival was also similar in the surgical and medical groups (63% and 53%, respectively). Median survival was >15 years in both the surgical and medical groups ( P =NS). The 15-year cumulative survival estimates in all subgroups were affected by convergence of the surgical and medical group survival curves caused by a disproportionate increase in late surgical group mortality. Overall, 26% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 65% would be estimated to have had surgery by 15 years. When the CASS Registry patients with LMEQ disease who participated in the randomized trial or who were randomizable were analyzed, CABG surgery did not prolong the 15-year cumulative survival estimates compared with nonsurgical therapy for randomized (71% versus 67%, respectively) and for randomizable patients (62% versus 92%, respectively) with an LV ejection fraction ≥50%. Conclusions This report, which extends follow-up of more than 16 years in CASS Registry patients with LMEQ disease, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (≥70%) also was present or in patients with an LV ejection fraction ≥50% who participated in the CASS randomized trial or who were randomizable. These results extend our understanding of the natural history of LMEQ disease and permit a more accurate estimate of long-term surgical and medical group survival. These long-term results should allow clinicians to make more informed decisions about the best choice of treatment available for patients with similar clinical and angiographic features.