Mean Society Of Thoracic Surgeons Research Articles

Does the disparity in baseline characteristics of patients undergoing transcatheter aortic valve replacement with 23 mm vs. 26 mm valves impact clinical outcome?

We sought to identify if baseline characteristic differences in patients who receive a 23 mm vs. 26 mm valve impact clinical outcomes. Transcatheter aortic valve replacement (TAVR) is currently an approved therapy for patients with severe aortic stenosis who are considered inoperable or are at high risk. We retrospectively examined baseline characteristics and outcomes of patients receiving a 23 mm (n = 132) vs. 26 mm valve (n = 81) via the transfemoral approach. Gender (P < 0.01), previous coronary artery bypass surgery (P < 0.01), history of atrial fibrillation (P = 0.04), and mean Society of Thoracic Surgeons (STS) score (P < 0.01) were significantly different between groups. There were no significant differences in the rates of minor/major vascular complications (2.2 vs. 3.7%, P = 0.68 and 13.0 vs. 12.3%, P = 0.89, respectively). Bleeding complications were also comparable (major bleed 2.3 vs. 1%, P >0.99, minor bleed 19.0 vs. 22.0%, P = 0.67 and life threatening bleed 7.0 vs. 5.0%, P = 0.77). In-hospital death (6.0 vs. 5.0%, P >0.99), 30-day all-cause death (7.6 vs. 6.2%, P = 0.69), and all-cause death at 1 year (17.4 vs. 25.9%, P = 0.13) were also similar between groups. Gender, valve size, previous coronary bypass surgery and atrial fibrillation were not independently associated with mortality; however, on multivariate analysis STS score was (HR 1.11; 95% CI 1.02-1.19; P = 0.01). Patients undergoing TAVR with 23 and 26 mm valves have similar clinical outcomes despite significant differences in baseline characteristics. © 2015 Wiley Periodicals, Inc.

Current state of transcatheter mitral valve repair with the MitraClip.

Many patients affected with mitral valve regurgitation suffer from multiple comorbidities. The MitraClip device provides a safe means of transcatheter valve repair in patients with suitable mitral valve anatomy who are at prohibitive risk for surgery. We describe our early procedural outcomes and present a summary of the current state of MitraClip technology in the United States. We performed a retrospective chart review of initial high-risk or inoperable patients who underwent MitraClip placement at our institution after completion of the EVEREST II study. We examined the primary outcome of 30-day mortality, and secondary outcomes included extent of reduction of mitral regurgitation (MR), New York Heart Association (NYHA) functional class improvement, length of stay, and major complications. A total of 115 high-risk patients (mean Society of Thoracic Surgeons predicted risk of mortality 9.4%±6.1%) underwent the MitraClip procedure at our institution between March 2009 and April 2014. Co-morbidities including coronary artery disease (67.8%), pulmonary disease (39.1%) and previous cardiac surgery (44.3%) were common. The device was placed successfully in all patients with a 30-day mortality of 2.6%. All patients demonstrated 3+ or 4+ MR on preoperative imaging, and 80.7% of patients had trace or 1+ MR at hospital discharge. NYHA class improved substantially, with 79% of patients exhibiting class III or IV symptoms pre-procedure and 81% reporting class I or II symptoms at one month follow-up. The MitraClip procedure provides a safe alternative to surgical or medical management for high-risk patients with MR and suitable valve anatomy. A comprehensive heart team approach is essential, with surgeons providing critical assessment of patient suitability for surgery versus percutaneous therapy as well as performance of the valve procedure.

5-year outcomes of transcatheter aortic valve replacement or surgical aortic valve replacement for high surgical risk patients with aortic stenosis (PARTNER 1): a randomised controlled trial

The Placement of Aortic Transcatheter Valves (PARTNER) trial showed that mortality at 1 year, 2 years, and 3 years is much the same with transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) for high-risk patients with aortic stenosis. We report here the 5-year outcomes. We did this randomised controlled trial at 25 hospitals, in Canada (two), Germany (one), and the USA (23). We used a computer-generated randomisation sequence to randomly assign high-risk patients with severe aortic stenosis to either SAVR or TAVR with a balloon-expandable bovine pericardial tissue valve by either a transfemoral or transapical approach. Patients and their treating physicians were not masked to treatment allocation. The primary outcome of the trial was all-cause mortality in the intention-to-treat population at 1 year, we present here predefined outcomes at 5 years. The study is registered with ClinicalTrials.gov, number NCT00530894. We screened 3105 patients, of whom 699 were enrolled (348 assigned to TAVR, 351 assigned to SAVR). Overall mean Society of Thoracic Surgeons Predicted Risk of Mortality score was 11·7%. At 5 years, risk of death was 67·8% in the TAVR group compared with 62·4% in the SAVR group (hazard ratio 1·04, 95% CI 0·86-1·24; p=0·76). We recorded no structural valve deterioration requiring surgical valve replacement in either group. Moderate or severe aortic regurgitation occurred in 40 (14%) of 280 patients in the TAVR group and two (1%) of 228 in the SAVR group (p<0·0001), and was associated with increased 5-year risk of mortality in the TAVR group (72·4% for moderate or severe aortic regurgitation vs 56·6% for those with mild aortic regurgitation or less; p=0·003). Our findings show that TAVR as an alternative to surgery for patients with high surgical risk results in similar clinical outcomes. Edwards Lifesciences.

Comparison of four contemporary risk models at predicting mortality after aortic valve replacement

Risk stratification for aortic valve replacement (AVR) is desirable given the increased demand for intervention and the introduction of transcatheter aortic valve implantation. We compared the prognostic utility of the European System for Cardiac Operative Risk Evaluation (EuroSCORE), EuroSCORE II, Society of Thoracic Surgeons (STS) score, and an Australasian model (Aus-AVR score) for AVR. We retrospectively calculated the 4 risk scores for patients undergoing isolated AVR at Auckland City Hospital from 2005 to 2012 and assessed their discrimination and calibration for short- and long-term mortality. A total of 620 patients were followed up for 3.8 ± 2.4 years, with an operative mortality of 2.9% (n = 18). The mean EuroSCORE, EuroSCORE II, STS score, and Aus-AVR score was 8.7% ± 8.3%, 3.8% ± 4.7%, 2.8% ± 2.7%, and 3.2% ± 4.8%, respectively. The corresponding C-statistics for operative mortality were 0.752 (95% confidence interval [CI], 0.652-0.852), 0.711 (95% CI, 0.607-0.815), 0.716 (95% CI, 0.593-0.837), and 0.684 (95% CI, 0.557-0.811). The corresponding Hosmer-Lemeshow test P and chi-square values for calibration were .007 and 21.1, .125 and 12.6, .753 and 5.0, and .468 and 7.7. The corresponding Brier scores were 0.0348, 0.0278, 0.0276, and 0.0294. Independent predictors of operative mortality included critical preoperative state, atrial fibrillation, extracardiac arteriopathy, and mitral stenosis. The log-rank test P values were all <.001 for mortality during follow-up for all 4 scores, stratified by quintile. All 4 risk scores discriminated operative mortality after isolated AVR. The EuroSCORE had poor calibration, overestimating operative mortality, although the other 3 scores fitted well with contemporary outcomes. The STS score was the best calibrated in the highest quintile of operative risk.

Transapical aortic valve implantation: predictors of survival up to 5 years in 730 patients. An update

A major limitation of transcatheter aortic valve implantation (TAVI) is that its long-term outcomes are still unknown. The purpose of this study was to evaluate survival up to 5 years after implantation and to identify predictors of follow-up mortality in a large cohort of patients who underwent exclusively a transapical TAVI procedure. Outcomes in terms of mortality and freedom from structural valve deterioration were evaluated in 730 consecutive patients. The median age was 80 years (range, 29-99 years). Forty patients (5.5%) presented with cardiogenic shock. The mean logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 35.0 ± 21.9%, the mean EuroSCORE II was 16.2 ± 16.2% and the mean Society of Thoracic Surgeons predicted operative mortality score was 14.0 ± 11.8%. According to allocation in EuroSCORE II quartiles, four equal subgroups of different risk profile were defined with low, intermediate, high and very high arithmetic risks. The overall 30-day mortality rate was 4.5% (33/730); 3.9% (27/690) in patients without cardiogenic shock. Survival at 1, 3 and 5 years were 80 ± 2%, 60 ± 2% and 41 ± 4%. Best survival up to 58 ± 7% at 5 years was found in the low and intermediate arithmetic risk quartile (P ≤ 0.001). In multivariable analysis, age (hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 1.03-1.06, P < 0.001), New York Heart Association class IV (HR: 1.69, CI: 1.28-2.23, P < 0.001), cardiogenic shock (HR: 2.80, CI: 1.73-4.54, P < 0.001), serum creatinine level (HR: 1.24, CI: 1.10-1.40, P < 0.001) and atrial fibrillation (HR: 1.66, CI: 1.27-2.16, P < 0.001) were predictive of follow-up mortality, whereas the absence of post-procedural acute kidney injury (HR: 0.50, CI: 0.38-0.67, P < 0.001) was protective against follow-up mortality. The freedom from structural valve deterioration requiring reoperation on the prosthesis was 95.7 ± 1.9% at 5 years. We identified three main causes of follow-up mortality: non-cardiac comorbidity, advanced stages of heart failure and procedure-related complications. Further improvements of the TAVI technique should concentrate on the complete exclusion of the latter.

PM121 Incidence and predictors of events following TAVI with a self-expanding valve: immediate and mid-term outcomes

O ST E R A B ST R A C T S Methods: A cohort of 8 patients with severe aortic stennosis underwent 9 BAV procedures. Intra-cardiac echocardiography (ICE) guided trans-septal puncture and BAV using Inoue balloon were performed antegradely. Clinical, hemodynamin, and follow-up mortality data were collected. Results: The mean age was 81.0 9.2 years, and the vast majority of patients had comorbidities and high-risk features including 4 hemodialysis patients(50%). The mean Society of Thoracic Surgeons and EuroSCOREII (European System for Cardiac Operative Risk Evaluation) was 10.6 5.2 and 16.0 7.8, respectively. BAV was performed for symptom relief in all patients (100%). The mean aortic valve area (AVA) increased from 0.69 0.32 cm(2) to 1.17 0.4 cm(2) (p 1 cm(2), and in 7 patients (88%), AVA increased by >50%. There was no death, stroke, coronary occlusion, severe aortic regurgitation, cardiac tamponade. One patient developed sepsis and worsening of renal failure. During median follow-up of 194 days, the mortality rate was 25% (n 1⁄4 2). Conclusion: In severe AS patients who have high risk for surgical AVR, antegrade BAV using Inoue balloon may be feasible with good initial and mid-term outcomes. Disclosure of Interest: None Declared

PM120 Sex influence on the results of the self expanding aortic prosthesis implantation according the criteria of the valve academic research consortium

O ST E R A B ST R A C T S Methods: A cohort of 8 patients with severe aortic stennosis underwent 9 BAV procedures. Intra-cardiac echocardiography (ICE) guided trans-septal puncture and BAV using Inoue balloon were performed antegradely. Clinical, hemodynamin, and follow-up mortality data were collected. Results: The mean age was 81.0 9.2 years, and the vast majority of patients had comorbidities and high-risk features including 4 hemodialysis patients(50%). The mean Society of Thoracic Surgeons and EuroSCOREII (European System for Cardiac Operative Risk Evaluation) was 10.6 5.2 and 16.0 7.8, respectively. BAV was performed for symptom relief in all patients (100%). The mean aortic valve area (AVA) increased from 0.69 0.32 cm(2) to 1.17 0.4 cm(2) (p 1 cm(2), and in 7 patients (88%), AVA increased by >50%. There was no death, stroke, coronary occlusion, severe aortic regurgitation, cardiac tamponade. One patient developed sepsis and worsening of renal failure. During median follow-up of 194 days, the mortality rate was 25% (n 1⁄4 2). Conclusion: In severe AS patients who have high risk for surgical AVR, antegrade BAV using Inoue balloon may be feasible with good initial and mid-term outcomes. Disclosure of Interest: None Declared

Improved Mitral Valve Performance After Transapical Aortic Valve Implantation

Concomitant mitral regurgitation (MR) is frequently present before the performance of transapical aortic valve implantation (TA-AVI). Our aim was to study the impact of MR on outcome and the effect of TA-AVI on MR using the Edwards SAPIEN prosthesis (Edwards Lifesciences, Irvine, CA). A total of 439 patients aged 81.5±6.4 years, 64.0% of whom were women, underwent TA-AVI between February 2006 and August 2011. The mean logistic EuroSCORE was 29.7%±15.7% and the mean Society of Thoracic Surgeons (STS) score was 11.4%±7.6%. Outcome was assessed in patients with absent (9.8%), mild or trivial (58.5%), moderate (29.7%), and severe (2.0%) MR by pre- and postoperative echocardiography. Patients with moderate/severe MR versus mild or trivial MR had an increased in-hospital mortality (adjusted hazard ratio [HR], 3.98; 95% confidence interval [CI], 1.79-8.84; p=0.001) but a comparable 4-year survival (adjusted HR, 1.29; 95% CI, 0.47-3.49; p=0.623). During postoperative echocardiographic examination, there was an overall improvement in mitral incompetence (absent in 23.6%, mild in 58.6%, moderate in 17.8%, and severe in none). Independent multivariate variables associated with improved MR were MR greater than 1+ (odds ratio [OR], 7.73; p<0.001), the presence of functional MR (OR, 3.66; p=0.011), left ventricular ejection fraction (LVEF) of 60% or more (OR, 3.28; p=0.002), and a mean transaortic gradient (OR, 1.03; p=0.005). Moderate/severe MR before TA-AVI is associated with an increased early, but a comparable late, mortality. We observed an overall improved mitral valve performance, possibly resulting from reducing both subvalvular traction and closure forces acting on the mitral valve.

Feasibility and efficacy of the 2.5 L and 3.8 L impella percutaneous left ventricular support device during high‐risk, percutaneous coronary intervention in patients with severe aortic stenosis

Assessment of the feasibility and outcomes of the 2.5 L and 3.8 L Impella cardiac pump in patients with severe aortic stenosis (AS) and left ventricular impairment undergoing percutaneous revascularization (PCI) with or without balloon aortic valvuloplasty (BAV). We reviewed the clinical and procedural findings from a consecutive series of unselected patients with severe AS who underwent PCI during Impella support. In addition, we describe novel "balloon-assist" techniques that allowed implantation of Impella into the left ventricle (LV) when initial unassisted attempts failed. Five patients with severe AS were identified (four males, age 78.2 years, aortic valve area (AVA) 0.6 cm(2) , left ventricular ejection fraction (LVEF) 24 ± 5%, mean Society of Thoracic Surgeons (STS) mortality 11% (range 3-17%)). The Impella catheter traversed the aortic valve (AV) unassisted in only one patient, with four cases requiring balloon-assist techniques. All patients underwent planned revascularisation; mean procedure time 177 min (range 135-252 min), mean number of stents 3.4 (range 1-8), with three patients requiring rotational atherectomy. All procedures were well tolerated, with absence of arrhythmia, hypotension, pulmonary edema, stroke, or myocardial infarction. One patient died 48 hr post-PCI of multi-organ failure. The four remaining patients were well at 30 days. Implantation of the 2.5 and 3.8 L Impella appears feasible in patients with severe AS and left ventricle (LV) impairment. A balloon-assist technique may be used to facilitate device implantation when initial unassisted attempts fail. Improved hemodynamic stability may enhance the tolerability of lengthy and complex procedures.

Comparison Between Different Risk Scoring Algorithms on Isolated Conventional or Transcatheter Aortic Valve Replacement

There are a number of scoring systems for risk evaluation in cardiac surgery, the most important of which are the European System for Cardiac Operative Risk Evaluation (EuroSCORE), The Society of Thoracic Surgeons (STS) score, the ACEF score (acronym for age, preoperative creatinine, and ejection fraction), and more recently, the new EuroSCORE-II. The aim of our study was to analyze and compare the predictive value of these scores in patients undergoing aortic valve replacement (AVR) or transcatheter aortic valve replacement (TAVR). A total of 1,512 consecutive patients undergoing either conventional AVR (n = 1,066) or TAVR (transfemoral, n = 291; transapical, n = 155) were enrolled. Logistic and additive EuroSCORE of all patients were 13.3% ± 13.2% and 7.8% ± 3.3%, on average. The mean STS score, ACEF score, and EuroSCORE-II were 5.7% ± 5.0%, 1.5% ± 0.7%, and 4.2% ± 4.9%, respectively. Overall mortality at 30 days was 6.3%. The area under the curve (AUC) was 73.8 for the logistic EuroSCORE and 73.5 for the additive EuroSCORE. The STS score gave an AUC of 70.8. The AUCs for the ACEF and EuroSCORE-II were 63.8 and 71.2, respectively. In the transfemoral TAVR group, AUCs were 59.8 and 59.3 for the logistic and additive EuroSCORE, respectively, 63.2 for the STS score, and 55.9 and 55.4 for the ACEF and EuroSCORE-II, respectively. In the transapical TAVR group, AUCs were 88.0 and 82.8 for the logistic and additive EuroSCORE, respectively, 79.0 for the STS score, and 61.7 and 83.7 for the ACEF and EuroSCORE-II, respectively. Overall, 30-day mortality was best predicted by the STS score. Discrimination threshold predicting mortality was equal between all other risk calculators. Surprisingly, the new EuroSCORE-II was not superior to other models in risk prediction for AVR and TAVR patients.

Comparison between STS score and logistic EuroSCORE for predicting mortality after percutaneous mitral valve repair

Purpose: The Logistic Euroscore (LES) and Society of Thoracic Surgeons (STS) score are used to identify high-risk or inoperable patients eligible for percutaneous Mitral Valve (MV) repair, using the edge-to-edge clip technique. We aimed to examine the correlation between LES and STS scores, and the performance characteristics in patients who underwent percutaneous MV repair. Methods: In total, 87 high-risk patients who underwent percutaneous MV repair using edge-to-edge technique between 01-2009 and 01-2013 were included. The performance of the LES and STS scores was evaluated. Results: The mean age of the included patients was 76.6±9.3 years (70.1% male), with a NYHA functional class ≥ 3 in 93.1%. The combination of in-hospital or 30-days mortality rate was 3.4%. The mean LES was 25.2±15.7%, and mean STS score 13.7±8.6%. A LES of ≥ 20% was present in 54% and a STS score ≥ 10% in 61% of patients. The Pearson correlation coefficient showed a moderate association between LES and STS score (r = 0.64, p<0.001). The area under the receiving operating curve for the prediction of in-hospital or 30-days mortality after percutaneous MV repair was 0.75 for LES and 0.66 for STS score. Conclusion: The LES and STS score are inadequate to predict mortality after percutaneous MV repair using the edge-to-edge technique in high-risk patients. Clinical judgment and the heart team should play a key role in selecting patients for percutaneous MV repair.

Predictors of Operative Mortality in Cardiac Surgical Patients with Prolonged Intensive Care Unit Duration

Several systems have been developed to predict mortality after intensive care unit (ICU) admission in medical and surgical patients. However, a similar tool specific to cardiac surgical patients with prolonged ICU duration does not exist. The purpose of the current study was to identify independent perioperative predictors of operative mortality among cardiac surgical patients with prolonged ICU duration. From 2003 to 2008, a total of 13,105 cardiac surgical patients with ICU durations >48hours were identified within a statewide database. Perioperative factors, including Society of Thoracic Surgeons Predicted Risk of Mortality, were evaluated. Univariate and multivariate analyses identified significant correlates of operative mortality and their relative strength of association as determined by the Wald chi-square statistic. Mean patient age was 66.8 ± 11.2 years, median ICU duration was 76.5 hours (range 56.0 to 124.0 hours), and mean Society of Thoracic Surgeons predicted risk of mortality was 4.4% ± 6.2%. Among preoperative and operative factors, intra-aortic balloon pump use, patient age, immunosuppressive therapy, hemodialysis requirement, cardiopulmonary bypass time, and heart failure proved to be the strongest correlates of mortality (all p < 0.05) on risk-adjusted multivariate analysis. Type of cardiac procedure had no significant association with mortality after risk adjustment. Among postoperative complications, cardiac arrest, prolonged mechanical ventilation (>24 hours), and stroke were the strongest predictors of risk-adjusted mortality (all p < 0.001). Operative mortality can be predicted by select risk factors for cardiac surgical patients with prolonged ICU duration. Patient age, preoperative intra-aortic balloon pump, postoperative cardiac arrest, prolonged ventilation, and stroke have the strongest association with mortality. Identification of these factors in the perioperative setting can enhance resource use and improve mortality after cardiac surgery.

Does the Society of Thoracic Surgeons risk score accurately predict operative mortality for patients with pulmonary hypertension?

This study assessed the impact of pulmonary hypertension (PH) on morbidity and mortality after the most common cardiac operations and evaluated the accuracy of the Society of Thoracic Surgeons (STS) risk model for patients with PH. At a single center between 1994 and 2010, all adult cardiac operations performed with recorded preoperative mean pulmonary arterial pressure (MPAP) and STS predicted mortality were reviewed. MPAP was defined as normal (<25 mm Hg) or as mild (25-34 mm Hg), moderate (35-44 mm Hg), or severe (≥ 45 mm Hg) PH. Multivariate analysis was performed to elucidate the contribution of PH to morbidity and mortality. In all, 3343 patient records were reviewed. Coronary artery bypass grafting (CABG) was the most common procedure (67.5%), followed by aortic valve replacement (24.9%) and mitral valve procedures (6.3%). Postoperative complications and mortality increased with increasing MPAP. Multivariable analysis found that both moderate (odds ratio, 7.17; P < .001) and severe (odds ratio, 13.73; P < .001) PH were significantly associated with increased mortality, even after accounting for STS risk. A subset analysis of isolated CABG cases revealed markedly increased mortality for all categories of PH (mild odds ratio, 1.99; moderate odds ratio, 11.5; severe odds ratio, 38.9; P < .001). Morbidity and mortality were independently associated with PH. Observed mortality was significantly higher than predicted by the STS model for patients with moderate and severe PH, particularly in isolated CABG. Addition of PH to the STS risk model should be considered, or alternative tools should be used to assess risk in these patients.

Percutaneous retrograde left ventricular assist support for interventions in patients with aortic stenosis and left ventricular dysfunction

To evaluate feasibility and technical outcomes in patients with aortic stenosis (AS) who have undergone high-risk procedures with continuous flow left ventricular (LV) assist, with the Impella 2.5 system (Abiomed, Danvers, MA). In preparation for transcatheter aortic valve implantation, an increasing number of high-risk patients with severe AS and left ventricular dysfunction are currently considered for percutaneous coronary interventions (PCI) and balloon aortic valvuloplasty (BAV). Hemodynamic support may be required in some patients. We reviewed procedural and clinical findings and 30-day outcomes in patients with symptomatic AS who underwent high-risk percutaneous procedures supported by the Impella 2.5 system. All patients carried a high-risk of operative mortality. Impella was used during PCI, BAV, and for hemodynamic support during emergencies. Over a 14-month period, 21 patients with AS underwent insertion of Impella prior to high-risk PCI (n = 3), BAV with subsequent PCI (n = 8), BAV alone (n = 7), or during cardiac arrest immediately following BAV (n = 3). The mean Society of Thoracic Surgeons (STS) predicted mortality risk was 14% (range 7.3-24.7%). Impella was inserted successfully in all patients attempted. Retrograde advancement of two catheters across the aortic valve (for concomitant BAV in 15 patients) was technically feasible. Retrograde continuous flow LV assist produced a reduction in LV end-diastolic pressure and an increase in arterial pressure. Periprocedural complications occurred in 19% (n = 4) patients, with no periprocedural deaths. Mortality at 30 days was 14.2%. Our data suggests that continuous flow LV assist with Impella 2.5 can be used in high-risk patients with severe AS who require periprocedural hemodynamic support.

Transapical aortic valve implantation using a new self-expandable bioprosthesis (ACURATE TA™): 6-month outcomes†

The ACURATE TA(™) Aortic Bioprosthesis and Delivery System (Symetis S.A., Ecublens, Switzerland) is a new transcatheter aortic valve designed for transapical implantation. The six-month results from the completed first-in-man study are reported. The Symetis ACURATE TA(™) is composed of a porcine biological tissue valve attached to a self-expandable nitinol stent. It allows for anatomical orientation and facilitates intuitive implantation providing tactile feedback. Since November 2009, a total of 40 high-risk elderly patients have been treated. The mean age of enrolled patients was 83.2 ± 4.0; 60.0% were female, with a mean logistic EuroSCORE of 21.2 ± 10.8% and a mean Society of Thoracic Surgeons (STS) score of 9.0 ± 4.7%. All implants were delivered successfully in the intra-annular and subcoronary position. One patient was converted to conventional surgery due to coronary impingement (after valve-in-valve implantation). One additional patient received valve-in-valve treatment (SAPIEN THV TA(™)). Five patients expired within 30 days and two additional patients expired during the 6-month follow-up due to non-valve-related causes resulting in a mid-term survival rate of 82.5%. Two patients suffered a stroke and another three required new onset pacemaker implantation. The mean aortic gradient significantly improved and remained stable throughout the follow-up (baseline: 51.9 ± 14.3 mmHg, 30 days: 12.3 ± 5.1 mmHg, 6 months: 11.9 ± 5.8 mmHg). At the 6-month follow-up, 96.7% of patients demonstrated either none/trace or mild (1+/4) paravalvular leakage only. According to the Valve Academic Research Council the device's success rate was 92.5%, with a 30-day safety profile of 25%. At the 6-month follow-up, the ACURATE TA(™) device showed stable valve function with low rates of paravalvular leakages. The cohort of high-risk patients demonstrated good clinical outcomes and 6-month survival.

Abstract 232: The Society of Thoracic Surgeons Mortality Risk Score Predicts 30-Day Hospital Readmissions

Introduction- Readmissions are associated with poor quality of care and unnecessary healthcare costs. Hence, minimizing unplanned hospital readmissions has become a priority among health care professionals and policymakers. Accurately predicting the risk for readmission could guide the efficient delivery of timely transitional care. Recently, the Society of Thoracic Surgeons (STS) risk score was used to predict hospital charges and resource use after aortic valve replacement. We hypothesize that the STS predicted mortality risk score could accurately discriminate which of the patients will be readmitted within 30 days. Methods- Clinical data from patients undergoing cardiac surgical procedures at four Intermountain hospitals over a three year period (1/2009 - 12/2011) were analyzed. The main outcome was 30-day all-cause acute care readmissions. The predicted mortality risk score was ascertained using the STS risk algorithm and categorized into tertiles based on the population distribution. Odds ratio (OR) estimates and 95% confidence intervals (CI) were obtained from logistic regression. Results- The overall mean STS predicted mortality risk score was 2.02 (SD = 3.12). The overall unadjusted readmission rate among the cardiac surgical cohort was 11.04%. Patients with a moderate mortality risk score (M = 1.13, SD = 0.28) were more likely (OR=1.45; 95% CI 1.00 - 2.08) to be readmitted than patients with a low mortality risk score (M = 0.46, SD = 0.14). Similarly, patients with a high mortality risk score (M = 4.48, SD = 4.47) had higher odds of readmission (OR=2.51; 95% CI 1.79 - 3.52). Conclusions- Our results suggest that the STS mortality risk score predicts 30-day all cause acute care readmissions. More research is warranted to investigate its clinical usefulness.

Mortality from isolated coronary bypass surgery: a comparison of the Society of Thoracic Surgeons and the EuroSCORE risk prediction algorithms

We compared the performances of the additive European System for Cardiac Operative Risk Evaluation, EuroSCORE (AES) and logistic EuroSCORE (LES) with the Society of Thoracic Surgeons' risk prediction algorithm in terms of discrimination and calibration in predicting mortality in patients undergoing isolated coronary artery bypass grafting (CABG) at a single institution in Pakistan. Both models were applied to 380 patients, operated upon at the Aga Khan University Hospital from August 2009 to July 2010. The actual mortality was 2.89%. The mean AES of all patients was 4.36±3.58%, the mean LES was 5.96±9.18% and the mean Society of Thoracic Surgeons' (STS) score was 2.30±4.16%. The Hosmer-Lemeshow goodness-of-fit test gave a P-value of 0.801 for AES, 0.699 for LES and 0.981 for STS. The area under the receiver operating characteristic curve was 0.866 for AES, 0.842 for LES and 0.899 for STS. STS outperformed AES and LES both in terms of calibration and discrimination. STS, however, underestimated mortality in the top 20% of patients having an STS score >2.88, thus overall STS estimates were lower than actual mortality. We conclude that STS is a more accurate model for risk assessment as compared to additive and logistic EuroSCORE models in the Pakistani population.

Minimally Invasive Mitral Valve Surgery Expands the Surgical Options for High-Risks Patients

A simplified minimally invasive mitral valve surgery (MIMVS) approach avoiding cross-clamping and cardioplegic myocardial arrest using a small (5 cm) right antero-lateral incision was developed. We hypothesized that, in high-risk patients and in patients with prior sternotomy, this approach would yield superior results compared to those predicted by the Society of Thoracic Surgeons (STS) algorithm for standard median sternotomy mitral valve surgery. Five hundred and four consecutive patients (249 males/255 females), median age 65 years (range 20-92 years) underwent MIMVS between 1/06 and 8/09. Median preoperative New York Heart Association function class was 3 (range 1-4). Eighty-two (16%) patients had an ejection fraction ≤35%. Forty-seven (9%) had a STS predicted mortality ≥10%. Under cold fibrillatory arrest (median temperature 28°C) without aortic cross-clamp, mitral valve repair (224/504, 44%) or replacement (280/504, 56%) was performed. Thirty-day mortality for the entire cohort was 2.2% (11/504). In patients with a STS predicted mortality ≥ 10% (range 10%-67%), the observed 30-day mortality was 4% (2/47), lower than the mean STS predicted mortality of 20%. Morbidity in this high-risk group was equally low: 1 of 47 (2%) patients underwent reexploration for bleeding, 1 of 47 (2%) patients suffered a permanent neurologic deficit, none had wound infection. The median length of stay was 8 days (range 1-68 days). This study demonstrates that MIMVS without aortic cross-clamp is reproducible with low mortality and morbidity rates. This approach expands the surgical options for high-risk patients and yields to superior results than the conventional median sternotomy approach.

Analysis of Survival in 300 High-Risk Patients up to 2.5 Years After Transapical Aortic Valve Implantation

Midterm results after transapical aortic valve implantation are still unknown in a large group of patients. We report our institutional experience in 300 high-risk patients. Since April 2008, transapical aortic valve implantation was performed in 300 patients (mean age, 80 ± 8 years). The mean logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 39% ± 19% and the mean Society of Thoracic Surgeons (STS) score was 19% ± 16%. Eighteen patients were in cardiogenic shock preoperatively. Follow-up was up to 31 months with a total of 3,500 months of follow-up. Technical success of the procedure was 99.7% (299 of 300 patients). The 30-day mortality rate in all patients without cardiogenic shock was 3.9%. The overall 30-day mortality for the whole group of 300 patients was 4.7%. The mortality of the last 100 patients dropped to 2.0%. The cumulative survival was 83% at 1 year, 76% at 1.5 years, and 65% at 2 years and beyond. In patients with lower risk scores, cumulative survival reached 78% at 2 years and beyond. The outcome of transapical aortic valve implantation in very high-risk patients was very favorable not only early after the procedure but also later on. Preoperative risk scores were not indicators for early mortality but were for later mortality. Survival was mainly influenced by noncardiac (renal, pulmonary, and vascular) comorbidities as well as by signs of advanced cardiac failure.

Acute Safety and 30-Day Outcome After Percutaneous Edge-to-Edge Repair of Mitral Regurgitation in Very High-Risk Patients

Percutaneous edge-to-edge mitral valve repair using the MitraClip device has evolved as a new tool for the treatment of severe mitral valve regurgitation. This technique has been evaluated in surgical low- and high-risk patients. Patients with advanced age, multiple morbidities, and heart failure will be the first to be considered for a nonsurgical approach. Thus safety and feasibility data in very high-risk patients are crucial for clinical decision making. The aim of this study was to assess short-term safety and clinical efficacy in high-risk patients with a Society of Thoracic Surgeons (STS) score >15% after MitraClip implantation (mean STS score 24 ± 4%). All relevant complications, mortality, echocardiographic improvement, and changes in brain natriuretic peptide, high-sensitive troponin T, 6-minute walk distance test, and New York Heart Association functional class were collected in patients within 30 days after MitraClip implantation. Mitral regurgitation had significantly decreased after 30 days from grade 2.9 ± 0.2 to 1.7 ± 0.7 (p < 0.0001). Accordingly, New York Heart Association functional class had significantly improved from 3.38 ± 0.59 to 2.2 ± 0.4 (p <0.001). Objective parameters of clinical improvement showed a significant increase in 6-minute walk distance test (from 194 ± 44 to 300 ± 70 m, p <0.01) and insignificant trends in brain natriuretic peptide (10,376 ± 1,996 vs 4,385 ± 1,266 ng/L, p = 0.06) and high-sensitive troponin T (43 ± 8.9 vs 36 ± 7.7 pg/L, p = 0.27) improvement. Thirty-day mortality was 0. Two patients developed a left atrial thrombus, 1 patient was on a ventilator for >12 hours, and 1 patient had significant access site bleeding. In conclusion, this study shows that percutaneous edge-to-edge mitral valve repair can be safely performed even in surgical high-risk patients with an STS score >15. At 1-month follow-up most patients showed persistent improvement in mitral regurgitation and a clinical benefit.