Syma L. Prince

Reliability of risk algorithms in predicting early and late operative outcomes in high-risk patients undergoing aortic valve replacement

OBJECTIVE Risk algorithms were used to identify a high-risk population for transcatheter aortic valve implantation instead of standard aortic valve replacement in patients with aortic stenosis. We evaluated the efficacy of these methods for predicting outcomes in high-risk patients undergoing aortic valve replacement. METHODS Data were collected on 638 patients identified as having isolated aortic valve replacement between January 1, 1998 and December 31, 2006, using The Society of Thoracic Surgeons (STS) database. Long-term survival was determined from the Social Security Death Index or family contact. Operative risk was calculated using the STS Predicted Risk of Mortality, the EuroSCORE logistic and additive algorithms, and the Ambler Risk Score. Patients at or above the 90th percentile of risk (8.38% for STS, 33.47% for logistic, 12% for additive, 14.3% for Ambler) were identified as high risk. We then compared actual with predicted mortality and each algorithms ability to identify patients with the worst long-term survival. RESULTS Operative mortality was 24 of 638 (3.76%). An additional 121 (19.0%) patients died during the follow-up study period (mean 4.2 +/- 2.7 years). Overall mortality was 145 of 638 (22.7%). Expected versus observed mortality for the high-risk group by algorithm was 13.3% versus 18.8% for STS, 50.9% versus 15.6% for logistic, 14.0% versus 11.9% for additive, and 19.0% versus 13.4% by Ambler. Long-term mortality, per high-risk group, was 64.1% in the STS Predicted Risk of Mortality, 45.3% in the logistic, 45.2% in the additive, and 40.2% in Ambler Risk Score. Logistic regression showed that the STS algorithm was the most sensitive in defining the patients most at risk for long-term mortality. CONCLUSION The STS Predicted Risk of Mortality most accurately predicted perioperative and long-term mortality for the highest risk patients having aortic valve replacement.

Minimally Invasive Pulmonary Vein Isolation and Partial Autonomic Denervation for Surgical Treatment of Atrial Fibrillation

BACKGROUND We seek to demonstrate the rationale and efficacy of a minimally invasive surgical approach to the treatment of atrial fibrillation (AF) that combines pulmonary vein antral isolation with targeted partial autonomic denervation. METHODS The literature supporting the rationale of this approach is reviewed. Seventy-four patients underwent video-assisted bilateral pulmonary vein antral isolation with confirmation of block and partial autonomic denervation with follow-up of 6 months or greater and have a long-term rhythm monitor at 6 months. RESULTS Success was defined as no episodes greater than 15 seconds of AF on long-term monitoring. Treatment was successful in 83.7% of patients with paroxysmal AF and 56.5% of patients with persistent/long-standing persistent AF. CONCLUSIONS There are evidence-based data that support both pulmonary vein electrical isolation and targeted partial autonomic denervation in the treatment of AF. These techniques can be combined in a minimally invasive surgical approach. Early data suggest this is a safe and efficacious approach for the treatment of paroxysmal AF. Techniques are being developed for the minimally invasive surgical treatment of persistent AF from an epicardial approach.

Elimination of cardiopulmonary bypass improves early survival for multivessel coronary artery bypass patients.

BACKGROUND Coronary artery bypass graft (CABG) surgery performed without cardiopulmonary bypass (CPB) is currently increasing in clinical practice. Decreased morbidity associated with off-pump (OP) CABG in selected risk groups examined in relatively small, single institution groups has been the focus of most recent studies. The purpose of this study was to determine the independent impact of CPB on early survival in all isolated multivessel CABG patients undergoing surgery in two large institutions with established experience in OPCABG techniques. METHODS A review of two large databases employed by multiple surgeons in the hospitals of two institutions identified 8,758 multivessel CABG procedures performed from January 1998 through July 2000. In all, 8,449 procedures were included in a multivariate logistic regression analysis to determine the relative impact of CPB on mortality independent of known risk factors for mortality. Procedures were also divided into two treatment groups based on the use of CPB: 6,466 had CABG with CPB (CABG-CPB), 1,983 had CABG without CPB (OPCABG). Disparities between groups were identified by univariate analysis of 17 preoperative risk factors and treatment groups were compared by Parsonnets risk stratification model. Finally, computer-matched groups based on propensity score for institution selection for OPCABG were combined and analyzed by a logistic regression model predicting risk for mortality. RESULTS CABG-CPB was associated with increased mortality compared with OPCABG by univariate analysis, 3.5% versus 1.8%, despite a lower predicted risk in the CABG-CPB group. CPB was associated with increased mortality by multiple logistic regression analysis with an odds ratio of 1.79 (95% confidence interval = 1.24 to 2.67). An increased risk of mortality associated with CPB was also determined by logistic regression analysis of the combined computer-matched groups based on OPCABG-selection propensity scores with an odds ratio of 1.9 (95% confidence interval = 1.2 to 3.1). CONCLUSIONS Elimination of CPB improves early survival in multivessel CABG patients. Rigorous attempts to statistically account for selection bias maintained a clear association between CPB and increased mortality. Larger multiinstitutional studies are needed to confirm these findings and determine the most appropriate application of OPCABG.

Influence of diabetes on mortality and morbidity: off-pump coronary artery bypass grafting versus coronary artery bypass grafting with cardiopulmonary bypass

BACKGROUND Myocardial revascularization in diabetic patients is challenging with no established optimum treatment strategy. We reviewed our coronary artery bypass grafting experience to determine the impact of eliminating cardiopulmonary bypass on outcomes in diabetic patients relative to nondiabetic patients. METHODS From January 1995 through December 1999, 9,965 patients, of whom 2,891 (29%) had diabetes, underwent isolated coronary artery bypass grafting. Diabetic and nondiabetic patients were further divided into groups on the basis of cardiopulmonary bypass use. Twelve percent (346 of 2,891) of diabetic patients and 12% (829 of 7,074) of nondiabetic patients underwent coronary artery bypass grafting without cardiopulmonary bypass; the remainder had coronary artery bypass grafting with cardiopulmonary bypass. Nineteen preoperative variables were compared among treatment groups by univariate analysis. RESULTS Patients undergoing coronary artery bypass grafting without cardiopulmonary bypass compared with those having coronary artery bypass grafting with cardiopulmonary bypass had higher mean predicted mortalities (diabetic, 3.96% versus 3.72%, p = 0.83; nondiabetic, 3.03% versus 2.86%, p = 0.79). In nondiabetic patients, coronary artery bypass grafting without cardiopulmonary bypass provides an actual and risk-adjusted survival advantage over coronary artery bypass grafting with cardiopulmonary bypass (1.81% versus 3.44%, p = 0.0127; risk-adjusted mortality, 1.79% versus 3.61%, p = 0.007). This survival benefit of coronary artery bypass grafting without cardiopulmonary bypass was not seen in diabetic patients (2.89% versus 3.69%, p = 0.452; risk-adjusted mortality, 2.19% versus 2.98%, p = 0.42). Diabetic patients undergoing coronary artery bypass grafting without cardiopulmonary bypass had fewer complications, including decreased blood product use (34.39% versus 58.4%, p = 0.001), and reduced incidence of prolonged ventilation (6.94% versus 12.10%, p = 0.005), atrial fibrillation (15.90% versus 23.26%, p = 0.002), and renal failure requiring dialysis (0.87% versus 2.75%, p = 0.036). CONCLUSIONS The survival advantage in nondiabetic patients treated with coronary artery bypass grafting without cardiopulmonary bypass is not apparent in diabetic patients. Coronary artery bypass grafting without cardiopulmonary bypass in diabetic patients is nevertheless associated with a significant reduction in morbidity.

Comparative Clinical Outcomes of Thymectomy for Myasthenia Gravis Performed by Extended Transsternal and Minimally Invasive Approaches

BACKGROUND Both transsternal and video-assisted thoracoscopic surgery (VATS) approaches are used for thymectomy in myasthenia gravis. We compared outcomes of simultaneous experiences in two institutions: one utilizing the transsternal approach exclusively, the other using VATS procedures for all patients. The Myasthenia Gravis Foundation of America guidelines were used to standardize reporting. METHODS Between March 1992 and September 2006, 95 thymectomies were performed for myasthenia gravis; 48 by VATS and 47 by transsternal approach. Preoperative classification and postoperative disease status were compared between the groups. RESULTS Mean age was 39.8 +/- 14.9 (VATS) versus 34.4 +/- 13.2 years (transsternal) (p = 0.07); the proportion of females was 52% versus 67% (p = 0.15); and preoperative duration of myasthenia gravis was 27 +/- 44 versus 20 +/- 45 months (p = 0.43), respectively. Clinical follow up was 89.5% complete at a mean of 6.0 +/- 4.0 years and 4.3 +/- 2.9 years (p = 0.03). The operative time was 128 +/- 34 minutes (VATS) versus 119 +/- 27 minutes (transsternal) (p = 0.22). The need for postoperative ventilation was 4.2% versus 16.2% (p = 0.07) and mean length of stay was 1.9 +/- 2.6 versus 4.6 +/- 4.2 days (p < 0.001). Thymomas were found in 8.3% of VATS versus 13.3% of transsternal patients (p = 0.44). No myasthenia gravis related deaths occurred and 95.8% of the VATS and 97.9% of the transsternal patients were in either complete stable remission, pharmacologic remission, or minimal manifestations status. In the VATS group, 13 of 17 (76.5%) patients stopped prednisone usage after surgery versus 5 of 14 (35.7%) in the transsternal group (p = 0.022). CONCLUSIONS Thymectomy is an effective treatment in patients with myasthenia gravis with equivalent clinical outcomes obtained by either approach.

Pulmonary vein isolation and autonomic denervation for the management of paroxysmal atrial fibrillation by a minimally invasive surgical approach.

BACKGROUND Advances in technology such as epicardial bipolar radiofrequency pulmonary vein isolation, ganglionated plexi identification, and isolation and thoracoscopic left atrial appendage exclusion have enabled less invasive surgical options for management of atrial fibrillation. METHODS We performed a prospective, nonrandomized study of consecutive patients with symptomatic paroxysmal atrial fibrillation undergoing a video-assisted, minimally invasive surgical ablation procedure. The procedure consisted of bilateral, epicardial pulmonary vein isolation with bipolar radiofrequency, partial autonomic denervation, and selective excision of the left atrial appendage. Minimum follow-up was 1 year with long-term monitoring (24-hour continuous, 14-day event or pacemaker interrogation). RESULTS Between March 2005 and January 2008, 52 patients (35 male), mean age 60.3 years (range, 42-79 years) underwent the procedure. The left atrial appendage was isolated in 88.0% (44/50). Average hospital stay was 5.2 days (range 3-10 days). There were no operative deaths or major adverse cardiac events. On long-term monitoring, freedom from atrial fibrillation/flutter/tachycardia was 86.3% (44/51) and 80.8% (42/52) at 6 and 12 months, respectively. Antiarrhythmic drugs were stopped in 33 of 37 patients and warfarin in 30 of 37 of the patients in whom ablation was successful at 12 months. Freedom from symptoms attributed to atrial fibrillation/flutter/tachycardia was 78.0% (39/50) at 6 months and 63.8% (30/47) at 12 months. CONCLUSIONS Minimally invasive surgical ablation is effective in the management of paroxysmal atrial fibrillation as evidenced by freedom from atrial arrythmias by long-term monitoring at 12 months. Measuring success using clinical symptoms underestimated clinical success as compared with long-term monitoring.

High-risk patients referred for transcatheter aortic valve implantation: management and outcomes.

BACKGROUND Aortic valve replacement (AVR) is the treatment of choice for critical aortic stenosis. Selected patients have not previously been referred for AVR because of excessive risk of mortality and morbidity with surgery. The option of transcatheter aortic valve implantation (TAVI) has increased referral of this high-risk cohort for therapeutic intervention. We report the management and outcomes of these patients. METHODS Patients referred for TAVI from December 2005 to December 2007 were evaluated and followed up for intermediate-term all cause mortality. Patients received medical management, TAVI, conventional AVR, or balloon valvuloplasty (BAV) based on risk profile, hemodynamic and echocardiographic criteria, physician judgment, or patient choice. Patients were compared for demographics, Society of Thoracic Surgeons predicted risk of mortality score, and outcomes after AVR, TAVI, or BAV. RESULTS One hundred five patients were referred for TAVI during a 24-month period. Fifty-two patients (49.5%) received medical management, 16 (15.2%) conventional AVR, 21 (20.0%) received TAVI, and 16 (15.2%) received BAV. Patients were classified as medical management because of physician or patient choice, not meeting TAVI criteria, or underevaluation for a possible procedure. For all patients the average length of follow-up was 159 +/- 147 days. Patients receiving BAV had a Society of Thoracic Surgeons predicted risk of mortality score greater than those having medical management, AVR, or TAVI. Thirty-day mortality was 1 of 16 patients (6.3%) for AVR, 2 of 21 patients (9.5%) with TAVI, 2 of 16 patients (12.5%) for BAV, and 7 of 52 patients (13.5%) for the medical management cohort. Overall mortality during follow-up was 42.3% (22 of 52 patients) for medical management, 19.1% (4 of 21 patients) for TAVI, 12.5% (2 of 16 patients) for AVR, and 37.5% (6 of 16 patients) for BAV. CONCLUSIONS The population of patients screened for transcatheter therapy is complex and heterogeneous. Medical management alone demonstrates a high mortality rate, and BAV, although providing transient symptomatic relief, does not favorably impact survival. The majority of referred patients (65.7%), including those that declined intervention, were candidates for some form of valve replacement therapy, either TAVI or AVR. Transcatheter aortic valve implantation can be performed in appropriately selected patients with good early and immediate-term outcomes.

Video-assisted thymectomy for myasthenia gravis: an update of a single institution experience

OBJECTIVE Video-assisted thymectomy was introduced in 1992 as a minimally invasive alternative for the treatment of myasthenia gravis. As experience with this technique is limited and follow-up short, we present this expanded and updated experience for purposes of validation of the technique. METHODS Thirty-eight video-assisted thymectomies for myasthenia gravis were performed in our institution between March 1992 and March 2002. Two patients were lost to follow-up. We analyzed clinical results of 36 patients (14 males and 22 females) with a mean age of 41.2 years. Preoperative clinical staging was assessed by the newly recommended Myasthenia Gravis Foundation of America Clinical Classification. Clinical status at follow-up was assessed by the Myasthenia Gravis Foundation of America Postintervention Status classification. RESULTS There was no perioperative mortality or long-term morbidity. One of 38 (2.6%) patients required conversion to limited thoracotomy for bleeding. The mean length of hospital stay was 1.64 days (range 0-8 days) with a median stay of 1 day. The mean length of follow-up is 53.24 months (range 4-126 months). Overall clinical improvement at follow-up was observed in 30 of 36 (83.0%) patients, with five of 36 (14.0%) patients in complete stable remission. CONCLUSIONS Video-assisted thymectomy for myasthenia gravis provides acceptable clinical long-term results by a minimally invasive approach comparable to standard surgical approaches to the disease. The presented data is reported in accordance with the new guidelines by Myasthenia Gravis Foundation of America Task Force for valid comparison with future studies.

Minimally invasive surgical ablation of atrial fibrillation: Six-month results

BACKGROUND A minimally invasive surgery for treatment of atrial fibrillation was developed with bilateral pulmonary vein isolation, mapping, and ablation of the ganglionic plexi and excision of the left atrial appendage. A prospective multicenter registry was created to evaluate the outcomes. METHODS The procedure was performed through bilateral minithoracotomies with video assistance. It included bilateral pulmonary vein isolation with bipolar radiofrequency with documentation of conduction block, location of ganglionic plexi by high-frequency stimulation, and appropriate ablation and left atrial appendage exclusion/excision. Clinical follow-up at 6 months included monitoring with electrocardiogram, Holter, event monitor, or pacemaker interrogation. RESULTS One hundred fourteen patients with 60 (52.6%) paroxysmal, 32 (28.1%) persistent, and 22 (19.3%) long-standing persistent atrial fibrillations were treated. The mean age was 59.5 +/- 10.6 years, and 69.3% were men. The mean follow-up period was 204 +/- 41 days (median 195). There were 2 (1.8%) operative mortalities. At 6-month follow-up, with long-term monitoring, 52/60 (86.7%) patients with paroxysmal fibrillations were in normal sinus rhythm and 43/60 (71.7%) were both in normal sinus rhythm and off antiarrhythmic drugs. The patients with persistent atrial fibrillation had a lower success rate, with 18/32 (56.3%) being in normal sinus rhythm and 46.9% both in normal sinus rhythm and off antiarrhythmic drugs; for long-standing persistent cases, 11/22 (50%) were in normal sinus rhythm and 7/22 (31.9%) were also off antiarrhythmic drugs. CONCLUSIONS Minimally invasive atrial fibrillation surgery is an effective treatment of paroxysmal atrial fibrillation at 6 months. Continuous event monitoring is necessary to accurately assess treatment results. A more extensive lesion set seems to be required for treatment of persistent atrial fibrillation.

Aortic Valve Replacement Surgery: Comparison of Outcomes in Matched Sternotomy and PORT ACCESS Groups

BACKGROUND In the past decade, minimally invasive approaches have been developed for aortic valve surgery. We reviewed our data to determine if the use of the PORT ACCESS technique has improved hospital morbidity and mortality. METHODS Data were collected on 90 patients who had a replacement of their aortic valve using PORT ACCESS procedures (PORT ACCESS aortic valve replacement [PAVR]). This group was then matched 1:4 to a control group having aortic valve replacement surgery using a standard sternotomy approach. RESULTS The two groups had no statistically significant differences in preoperative risk factors. The perioperative and 30-day outcomes from the matched AVR and PAVR groups showed no mortalities in the PAVR group and 3.1% in the AVR group. Mean length of stay was shorter for PAVR patients (7.2 +/- 5.0 days; median 6 days) compared with the mean stay in the sternotomy group (8.5 +/- 9.5 days; median 6 days), PAVR patients also had statistically significant shorter intensive care unit stays, and time on ventilator. The number of patients needing ventilator support postoperatively was significantly lower in the PORT ACCESS group. Cross-clamp and perfusion times were longer in the PAVR group. No other morbidity was significantly different between groups, except for postoperative tamponade (higher in PAVR group). CONCLUSIONS In this analysis of matched patients, the patients having aortic valve replacement using PORT ACCESS procedures, spent a shorter time in the intensive care unit and had less need for postoperative ventilator usage (both number of patients using a ventilator and the mean time of use) in comparison with patients undergoing conventional sternotomy.