David F. Torchiana

Cardiac operations in patients 80 years old and older.

BACKGROUND Because the elderly are increasingly referred for operation, we reviewed results with cardiac surgical patients 80 years old or older. METHODS Records of 600 consecutive patients 80 years old or older having cardiac operations between 1985 and 1995 were reviewed. Follow-up was 99% complete. RESULTS Two hundred ninety-two patients had coronary grafting (CABG), 105 aortic valve replacement (AVR), 111 AVR + CABG, 42 mitral valve repair/ replacement (MVR) +/- CABG, and 50 other operations. Rates of hospital death, stroke, and prolonged stay (> 14 days) were as follows: CABG: 17 (5.8%), 23 (7.9%) and 91 (31.2%); AVR: 8 (7.6%), 1 (1.0%), and 31 (29.5%); AVR + CABG: 7 (6.3%), 12 (10.8%), and 57 (51.4%); MVR +/- CABG: 4 (9.5%), 3 (7.1%), and 16 (38.1%); other: 9 (18.0%), 3 (6.0%), and 23 (46.0%). Multivariate predictors (p < 0.05) of hospital death were chronic lung disease, postoperative stroke, preoperative intraaortic balloon, and congestive heart failure; predictors of stroke were CABG and carotid disease; and predictors of prolonged stay were postoperative stroke and New York Heart Association class. Actuarial 5-year survival was as follows: CABG, 66%; AVR, 67%; AVR + CABG, 59%; MVR +/- CABG, 57%; other, 48%; and total, 63%. Multivariate predictors of late death were renal insufficiency, postoperative stroke, chronic lung disease, and congestive heart failure. Eighty-seven percent of patients believed having a heart operation after age 80 years was a good choice. CONCLUSIONS Cardiac operations are successful in most octogenarians with increased hospital mortality, postoperative stroke, and longer hospital stay. Long-term survival is largely determined by concurrent medical diseases.

Influence of implantable cardioverter-defibrillators on the long-term prognosis of survivors of out-of-hospital cardiac arrest.

BACKGROUND Survivors of out-of-hospital cardiac arrest not associated with acute myocardial infarction are at high risk for recurrent cardiac arrest and sudden cardiac death. The impact of the implantable cardioverter-defibrillator on long-term prognosis in these patients is uncertain. METHODS AND RESULTS Three hundred thirty-one survivors of out-of-hospital cardiac arrest (age, 56 +/- 13.7 years) underwent electrophysiologically guided therapy. Implantable defibrillators were placed in 150 patients (45.3%), and 181 patients (54.7%) received pharmacological and/or surgical therapy alone. Left ventricular ejection fraction was 35.2 +/- 16.6% in defibrillator recipients and 45.3 +/- 18.2% in nondefibrillator patients. Median patient follow-up was 24 months in the defibrillator group and 46 months in the nondefibrillator group. In a proportional hazards model, the independent predictors of total cardiac mortality were left ventricular ejection fraction of less than 0.40 (relative risk, 4.55; 95% confidence interval, 2.44 to 8.33; P = .0001), absence of an implantable defibrillator (relative risk, 2.70; confidence interval, 1.41 to 5.00; P = .017), and persistence of inducible sustained ventricular tachycardia (relative risk, 1.84; 95% confidence interval, 0.97 to 3.49; P = .045). The 1- and 5-year probabilities of survival free of cardiac mortality in patients with left ventricular ejection fraction of less than 0.40 were 94.3% and 69.6% with a defibrillator and 82.1% and 45.3% without a defibrillator, respectively. For patients with left ventricular ejection fraction of 0.40 or more, the 1- and 5-year probabilities of survival free of cardiac mortality were 97.7% and 94.6% with a defibrillator and 95.4% and 86.9% without a defibrillator, respectively. CONCLUSIONS In survivors of out-of-hospital cardiac arrest, the implantable defibrillator is associated with a reduction in cardiac mortality, particularly in patients with impaired left ventricular function.

Efficacy and Safety of Ibutilide Fumarate for the Conversion of Atrial Arrhythmias After Cardiac Surgery

BACKGROUND Atrial arrhythmias occur commonly after cardiac surgery and are a cause of significant morbidity and increased hospital costs, yet there is no well-studied treatment strategy to deal with them expeditiously. The purpose of this study was to determine the efficacy and safety of ibutilide fumarate, an approved drug for the rapid conversion of atrial fibrillation and flutter, in patients after cardiac surgery. METHODS AND RESULTS Patients with atrial fibrillation or flutter occurring 1 to 7 days after surgery and lasting 1 hour to 3 days were randomized to receive two 10-minute blinded infusions of placebo or 0.25, 0.5, or 1.0 mg of ibutilide fumarate. Treatment was considered successful if sinus rhythm was restored for any period of time by hour 1.5. A total of 302 patients were randomized, 201 with fibrillation and 101 with flutter. Treatment with ibutilide resulted in significantly higher conversion rates than placebo, and efficacy was dose related (placebo 15%; ibutilide 0.25 mg 40%, 0.5 mg 47%, and 1.0 mg 57%). Conversion rates at all doses were higher for atrial flutter than for atrial fibrillation. Mean time to conversion decreased as the dose was increased. Polymorphic ventricular tachycardia was the most serious adverse effect and occurred in 1.8% of the ibutilide-treated patients compared with 1.2% of patients who received placebo. CONCLUSIONS Ibutilide is a useful and safe treatment alternative for the atrial arrhythmias that occur after cardiac surgery.

Mitral valve reconstruction versus replacement for degenerative or ischemic mitral regurgitation

Between January 1985 and June 1992, 263 consecutive patients had mitral valve reconstruction (133 patients) or replacement (130 patients) for degenerative or ischemic mitral regurgitation. The two groups were similar in sex, age, prior infarctions or cardiac operations, hypertension, angina, and functional class. Both groups were similar in mean ejection fraction, pulmonary artery pressure, cardiac index, and incidence of coronary artery disease. More reconstruction than replacement patients had ischemic etiology (22 [16%] versus 12 [9%]; p = not significant), and fewer reconstruction patients had ruptured anterior leaflet chordae (9 [7%] versus 39 [30%]; p < 0.01). More reconstruction than replacement patients had concomitant cardiac procedures (67 [50%] versus 59 [45%]; p = not significant). Hospital death occurred in 4 reconstruction patients (3%) and 15 (12%) replacement patients (p < 0.01). Median postoperative stay was shorter in reconstruction patients (10 versus 12 days; p = 0.02). Late valve-related death occurred in 3 reconstruction patients (2%) and 8 (6%) replacement patients (p = 0.08). Six-year actuarial freedom from thromboembolism was 92% for the reconstruction group and 85% for the replacement group (p = 0.12). Freedom from all valve-related morbidity and mortality was 85% for the reconstruction patients and 73% for the replacement patients (p = 0.03). Significant multivariate predictors of hospital death were age, mitral valve replacement, functional class, congestive heart failure, no posterior chordal rupture, and nonelective operation. Mitral valve reconstruction, when technically feasible, is the procedure of choice for degenerative or ischemic mitral regurgitation because of significantly lower hospital mortality and late valve-related events.

Limitations and Late Complications of Third-Generation Automatic Cardioverter-Defibrillators

BACKGROUND This study examines the limitations and complex management problems associated with the use of tiered-therapy, implantable cardioverter-defibrillators (ICDs). METHODS AND RESULTS The study group comprises the first 154 patients undergoing implantation of tiered-therapy ICDs at our institution. Pulse generators from three different manufacturers were used. In 39 patients, a complete nonthoracotomy lead system was used. The perioperative mortality was 1.3%. Of these 154 patients, 37% experienced late postoperative problems. Twenty-one patients required system revision within 36.5 months (mean, 8.57 +/- 11.3) of surgery. Reasons for revision were spurious shocks due to electrode fractures (3) or electrode adapter malfunction (2), inadequate signal from endocardial rate-sensing electrodes (3), superior vena cava or right ventricular coil migration (5), failure to correct tachyarrhythmias due to a postimplant rise in defibrillation threshold (5), or pulse generator failure (3). One of these patients required system removal for infection after revision of an endocardial lead. A further 32 patients received inappropriate shocks for atrial fibrillation with a rapid ventricular response or sinus tachycardia. Two of these patients also received shocks for ventricular tachycardia initiated by antitachycardia pacing triggered by atrial fibrillation. Ventricular pacing for bradycardia was associated with inappropriate shocks due to excessive autogain in 2 patients. CONCLUSIONS Despite the major diagnostic and therapeutic advantages of tiered-therapy ICDs, a significant proportion of patients continue to experience hardware-related complications or receive inappropriate shocks.

Risk of Reoperative Valve Replacement for Failed Mitral and Aortic Bioprostheses

BACKGROUND One factor influencing the choice of mechanical versus bioprosthetic valves is reoperation for bioprosthetic valve failure. To define its operative risk, we reviewed our results with valve reoperation for bioprosthetic valve failure. METHODS Records of 400 consecutive patients having reoperative mitral, aortic, or mitral and aortic bioprosthetic valve replacement from January 1985 to March 1997 were reviewed. RESULTS Reoperations were for failed bioprosthetic mitral valves in 219 patients, failed aortic valves in 153 patients, and failed aortic and mitral valves in 28 patients. Including 26 operations (6%) for acute endocarditis, 153 operations (38%) were nonelective. One hundred nine patients (27%) had other valves repaired or replaced, and 72 (18%) had coronary bypass grafting. The incidence of death in the mitral, aortic, and double-valve groups was respectively, 15 (6.8%), 12 (7.8%), and 4 (14.3%); and the incidence of prolonged postoperative hospital stay (>14 days) was, respectively, 57 (26.0%), 41 (26.8%), and 8 (28.6%). Only 7 of 147 patients (4.8%) having elective, isolated, first-time valve reoperation died. Multivariable predictors (p < 0.05) of hospital death were age greater than 65 years, male sex, renal insufficiency, and nonelective operation; and predictors of prolonged stay were acute endocarditis, renal insufficiency, any concurrent cardiac operation, and elevated pulmonary artery systolic pressure. CONCLUSIONS Reoperative bioprosthetic valve replacement can be performed with acceptable mortality and hospital stay. The best results are achieved with elective valve replacement, without concurrent cardiac procedures.

Accurate Localization of Mitral Regurgitant Defects Using Multiplane Transesophageal Echocardiography

BACKGROUND Appropriate patient selection for surgical repair of the mitral valve depends on the specific location and mechanism of regurgitation, which, in turn, has necessitated a more detailed method to accurately describe mitral pathology. This study tests a strategy of using multiplane transesophageal echocardiography to systematically localize mitral regurgitant defects and compares these results with the surgical findings. METHODS Fifty patients with mitral regurgitation underwent intraoperative transesophageal echocardiography for the evaluation of mitral pathology and potential repair. Mitral regurgitant defects were localized using a systematic strategy and a simple nomenclature that divides each mitral valve into six sections (three sections per leaflet) and each prosthetic sewing ring into six sections (60 radial degrees = one section). RESULTS Thirty-nine patients with native mitral valves were studied, for a total of 234 sections evaluated. Eighty-seven of these sections contained regurgitant defects by transesophageal echocardiography (mean number of regurgitant defects per valve, 2.2; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 96% (224/234; p < 0.0001) of the sections. Eleven patients with prosthetic mitral valves were studied, for a total of 66 sections evaluated. Twenty-three of these sections contained paravalvular leaks by transesophageal echocardiography (mean number of leaks per prosthesis, 2.1; range, 1 through 6). There was agreement between the transesophageal echocardiographic and surgical localizations in 88% (58/66; p < 0.001) of the sections. CONCLUSIONS This transesophageal echocardiographic strategy provides a systematic method to accurately localize mitral regurgitant lesions and has the potential to improve the preoperative assessment of patients with significant mitral regurgitation.

Virtual Fixtures for Robotic Cardiac Surgery

We are developing virtual fixtures for the internal mammary artery (IMA) harvest portion of robot-assisted coronary artery bypass graft procedures. A preoperative CT scan will be processed to define the location of the IMA. In surgery, the patients anatomy will be registered to the image data, then a virtual fixture will constrain the instruments motions, as commanded by the surgeon, to appropriate paths adjacent to the artery. As a preliminary test, a virtual wall is implemented on a commercial surgical robot system. Results from a dissection task show that execution is faster and more precise than with conventional freehand techniques.

Intraaortic balloon pumping for cardiac support: Trends in practice and outcome, 1968 to 1995

OBJECTIVES A total of 4756 cases of intraaortic balloon pump support have been recorded at the Massachusetts General Hospital since the first clinical insertion for cardiogenic shock in 1968. This report describes the patterns of intraaortic balloon use and associated outcomes over this time period. METHODS A retrospective record review was conducted. RESULTS Balloon use has increased to more than 300 cases a year at present. The practice of balloon placement for control of ischemia (2453 cases, 11.9% mortality) has become more frequent, whereas support for hemodynamic decompensation (congestive heart failure, hypotension, cardiogenic shock) has been relatively constant (1760 cases, 38.2% mortality). Mean patient age has increased from 54 to 66 years, and mortality has fallen from 41% to 20%. Sixty-five percent (3097/4756) of the total patient population receiving balloon support underwent cardiac surgery. Placement before the operation (2038 patients) was associated with a lower mortality (13.6%) than intraoperative (771 patients, 35.7% mortality) or postoperative use (276 patients, 35.9% mortality). Independent predictors of death with balloon pump support were insertion in the operating room or intensive care unit, transthoracic insertion, age, procedure other than angioplasty or coronary artery bypass, and insertion for cardiogenic shock. Independent predictors of death with intraoperative balloon insertion were age, mitral valve replacement, prolonged cardiopulmonary bypass, urgent or emergency operation, preoperative renal dysfunction, complex ventricular ectopy, right ventricular failure, and emergency reinstitution of cardiopulmonary bypass. CONCLUSIONS Balloons are being used more frequently for control of ischemia in more patients who are elderly with lower mortality. An institutional bias toward preoperative use of the balloon pump appears to be associated with improved outcomes.

Gastrointestinal Complications in Patients Undergoing Heart Operation: An Analysis of 8709 Consecutive Cardiac Surgical Patients

Introduction:Gastrointestinal (GI) complications following heart operation may be life-threatening. Systematic analysis of risk factors to allow early identification of patients at risk for GI complication may lead to the development of strategies to mitigate this complication as well as to optimize management after its occurrence. Methods:Of 8709 consecutive patients undergoing heart operation during 7 years (1997–2003), 46 (0.53%) developed GI complications requiring surgical consultation. Preoperative, intraoperative, and postoperative predictors of complication and death were identified and compared with a control group. Results:Significant (P < 0.05) preoperative predictors of complication were prior cerebrovascular accident (CVA), chronic obstructive pulmonary disease (COPD), type II heparin-induced thrombocytopenia, atrial fibrillation, prior myocardial infarction, renal insufficiency, hypertension, and need for intra-aortic balloon counter-pulsation. The most frequent serious GI complication was mesenteric ischemia, which developed in 31 (67%) patients. Twenty-two (71%) of these patients were explored, and 14 (64%) died within 2 days of heart operation. Of the 9 patients with mesenteric ischemia who were not explored, 7 (78%) died within 3 days of heart operation. Other complications included diverticulitis (5), pancreatitis (4), peptic ulcer disease (4), and cholecystitis (2). The mortality rate in this group of other diagnoses was lower (40%), and death occurred later (32 days) after heart operation (P = 0.03 compared with mesenteric ischemia). Predictors of death from GI complication included New York Heart Association (NYHA) class III and IV heart failure, smoking, chronic obstructive pulmonary disease, history of syncope, aspartate aminotransferase (AST) >600U/L, direct bilirubin >2.4mg/dL, pH < 7.30, and the need for >2 pressors. Conclusions:The most common catastrophic GI complication after cardiac surgery is mesenteric ischemia, which is frequently fatal. This complication may be a result of atheroembolization, heparin-induced thrombocytopenia, or hypoperfusion. Techniques to reduce the occurrence of and/or preemptively diagnosis postcardiotomy mesenteric ischemia are necessary to decrease its associated mortality.