Conventional aortic valve replacement remains a safe option in patients aged > or = 70 years: a 20-year experience.

BACKGROUND AND AIM OF THE STUDY: Increased life expectancy has resulted in the elderly frequently presenting with severe aortic stenosis. It has therefore become important to define indications for conventional aortic valve replacement (AVR) and transcatheter aortic valve implantation (TAVI) in this patient population. Thus, patients aged > or = 70 years undergoing conventional isolated AVR were evaluated for predictors of early and late mortality. METHODS: A retrospective analysis was conducted of prospectively collected data available from 1,061 consecutive patients (age range: 70-94 years) who underwent isolated AVR between 1982 and 2002. The patient age groups were 70-74 years (n = 466), 75-79 years (n = 367), and > or = 80 years (n = 228). The mean follow up was 6.0 +/- 4.4 years, and the total follow up 6,390 patient-years. Twenty-two variables were considered as potential risk factors for early and late mortality. RESULTS: Early mortality was higher in patients aged > or = 80 years than in those aged 70-79 years. Early mortality in patients aged > or = 80 years was lower between 1998 and 2002 than between 1982 and 1997. Multivariate predictors of early mortality were age > or = 80 years, operative status, previous intervention, renal failure, and mitral regurgitation. The early nonfatal complication rate was similar for patients aged 70-79 years and > or = 80 years, but late mortality was lower between 1998 and 2002 than between 1982 and 1997 in patients aged 70-79 years, and in those aged > or = 80 years. The 10-year actuarial survivals after AVR in patients aged 70-74, 75-79, and > or = 80 years were 54 +/- 3.0%, 43 +/- 3.8% and 17 +/- 3.9%, respectively. Multivariate predictors of late mortality were age 75-79 years, age > or = 80 years, peripheral vascular disease (PVD) and chronic obstructive pulmonary disease (COPD). Female gender was shown to be protective. CONCLUSION: Early mortality was higher in patients aged > or = 80 years undergoing AVR, though this has declined recently and is currently at an acceptable level. Other important predictors of mortality in elderly patients undergoing AVR are operative status, previous interventions, renal failure, mitral regurgitation, male gender, PVD, and COPD. Thus, conventional AVR remains a safe treatment option for the elderly patient.

Transcatheter valve-in-valve implantation for failed bioprosthetic heart valves.

BACKGROUND: The majority of prosthetic heart valves currently implanted are tissue valves that can be expected to degenerate with time and eventually fail. Repeat cardiac surgery to replace these valves is associated with significant morbidity and mortality. Transcatheter heart valve implantation within a failed bioprosthesis, a "valve-in-valve" procedure, may offer a less invasive alternative. METHODS AND RESULTS: Valve-in-valve implantations were performed in 24 high-risk patients. Failed valves were aortic (n=10), mitral (n=7), pulmonary (n=6), or tricuspid (n=1) bioprostheses. Implantation was successful with immediate restoration of satisfactory valve function in all but 1 patient. No patient had more than mild regurgitation after implantation. No patients died during the procedure. Thirty-day mortality was 4.2%. Mortality was related primarily to learning-curve issues early in this high-risk experience. At baseline, 88% of patients were in New York Heart Association functional class III or IV; at the last follow-up, 88% of patients were in class I or II. At a median follow-up of 135 days (interquartile range, 46 to 254 days) and a maximum follow-up of 1045 days, 91.7% of patients remained alive with satisfactory valve function. CONCLUSIONS: Transcatheter valve-in-valve implantation is a reproducible option for the management of bioprosthetic valve failure. Aortic, pulmonary, mitral, and tricuspid tissue valves were amenable to this approach. This finding may have important implications with regard to valve replacement in high-risk patients.

Transcatheter aortic valve implantation: lessons from the learning curve of the first 270 high-risk patients.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is a rapidly evolving strategy for therapy of aortic stenosis. We describe the effect of the learning curve from the first 270 high-risk patients in Vancouver, Canada. METHODS: Patients underwent TAVI by transfemoral (63%) or transapical (37%) routes using balloon expandable valves. The experience was divided into the first half (FH, patients 1-135) and second half (SH, patients 136-270). RESULTS: The mean age was 83.2 ± 8 years (FH 83 ± 12 vs. SH 81 ± 7 years, P = 0.12). The mean Society of Thoracic Surgeons Score (STS) was 9.5% ± 5.2%- FH 10.5 vs. SH 8.5% (P = 0.01). The overall procedural success rate in the FH was 92.6%, improving to 97.8% in the SH (P = 0.05). The transfemoral procedural success improved-FH 89.3% to SH 98.8% (P = 0.01). The transapical procedural success remained high-FH 98.0% to SH 96.1% (P = 0.53). The overall 30-day mortality was 9.6%, improving from FH 13.3% to SH 5.9% (P = 0.04). In the transfemoral cases, 30-day mortality decreased by 56% [10.7-4.7%, P = 0.14], and similarly in transapical cases [17.6-7.8%, P = 0.14]. In-hospital stroke occurred in 3.3% (FH 3.7% vs. SH 2.9%, P = 0.74). The overall need for a new permanent pacemaker was 5.9% (FH 5.9% vs. SH 5.9%, P = 1). The overall major vascular injury rate was 6.7% (FH 8.1% vs. SH 5.2%, P = 0.33). The overall incidence of coronary vessel occlusion was 1.1% (FH 1.5 % vs. SH 0.7%, P = 0.56). Device embolization or failure to cross the valve was rare and largely seen in the FH only. Procedural experience (>135 procedures) was an independent predictor of 30-day survival (HR: 6.7, 95% CI: 1.2-18.1, P = 0.03). CONCLUSION: TAVI outcomes improve with experience and device development. While overall complication rates are low, scope remains to further reduce procedural adverse events.

Radiofrequency therapy improves exercise capacity of mice with emphysema.

Emphysema is a common phenotype of chronic obstructive pulmonary disease (COPD). Although resection of emphysematous tissue can improve lung mechanics, it is invasive and fraught with adverse effects. Meanwhile, radiofrequency (RF) treatment is an extracorporeal method that leads to tissue destruction and remodeling, resulting in "volume reduction" and overall improvement in lung compliance of emphysematous lungs. Whether these changes lead to improved exercise tolerance is unknown. Here, we investigated the effectiveness of RF treatment to improve the exercise capacity of mice with emphysema. Fifty-two mice (7 weeks of age) were used in this experiment. A bilateral emphysema model was created by intratracheally instilling porcine pancreatic elastase (PPE) (1.5U/100 g body weight). RF treatment (0.5 W/ g body weight) was administered extracorporeally 14 days later and mice were sacrificed after another 21 days. The exercise capacity of mice was measured using a treadmill. Treadmill runs were performed just before PPE instillation (baseline), before RF treatment and before sacrifice. Following sacrifice, lung compliance and mean linear intercept (Lm) were measured and fibrosis was assessed using a modified Ashcroft score. There were 3 experimental groups: controls (instilled with saline, n = 12), emphysema (instilled with porcine pancreatic elastase, PPE, n = 11) and emphysema + treatment (instilled with PPE and given RF, n = 9). At endpoint, the maximum velocity of the emphysema + treatment group was significantly higher than that of the emphysema group, indicating improved exercise tolerance (86.29% of baseline vs 61.69% of baseline, p = 0.01). Histological analysis revealed a significant reduction in emphysema as denoted by Lm between the two groups (median 29.60 µm vs 35.68 µm, p = 0.03). The emphysema + treatment group also demonstrated a higher prevalence of lung fibrosis (≧Grade 3) compared with the emphysema group (11.7% vs 5.4%, p < 0.01). No severe adverse events from RF were observed. RF treatment improved the exercise capacity of mice with emphysema. These data highlight the therapeutic potential of RF treatment in improving the functional status of patients with COPD.

Transcatheter aortic valve implantation: impact on clinical and valve-related outcomes.

BACKGROUND: Transcatheter aortic valve implantation is an alternative to open heart surgery in patients with aortic stenosis. However, long-term data on a programmatic approach to aortic valve implantation remain sparse. METHODS AND RESULTS: Transcatheter aortic valve implantation was performed in 168 patients (median age, 84 years) in the setting of severe aortic stenosis and high surgical risk. Access was transarterial (n=113) or, in the presence of small iliofemoral artery diameter, transapical (n=55). The overall success rate was 94.1% in this early experience. Intraprocedural mortality was 1.2%. Operative (30-day) mortality was 11.3%, lower in the transarterial group than the transapical group (8.0% versus 18.2%; P=0.07). Overall mortality fell from 14.3% in the initial half to 8.3% in the second half of the experience, from 12.3% to 3.6% (P=0.16) in transarterial patients and from 25% to 11.1% (P=0.30) in transapical patients. Functional class improved over the 1-year postprocedure period (P<0.001). Survival at 1 year was 74%. The bulk of late readmission and mortality was not procedure or valve related but rather was due to comorbidities. Paravalvular regurgitation was common but generally mild and remained stable at late follow-up. At a maximum of >3 years and a median of 221 days, structural valve failure was not observed. CONCLUSIONS: Transcatheter aortic valve implantation can result in early and sustained functional improvement in high-risk aortic stenosis patients. Late outcome is determined primarily by comorbidities unrelated to aortic valve disease.

Novel polymorphism of interleukin-18 associated with greater inflammation after cardiac surgery.

INTRODUCTION: Interleukin (IL)-18 is a key modulator of the cytokine response that leads to organ dysfunction and prolonged intensive care unit (ICU) stay after cardiopulmonary bypass surgery. We hypothesised that variation in the pro-inflammatory gene IL-18 is associated with adverse clinical outcome because of a more intense inflammatory response. METHODS: Haplotypes of the IL-18 gene were inferred from genotypes of 23 Coriell Registry subjects. Four haplotype tag single nucleotide polymorphisms (-607 C/A, -137 G/C, 8148 C/T and 9545 T/G) identified four major haplotype clades. These polymorphisms were genotyped in 658 Caucasian patients undergoing cardiopulmonary bypass surgery. Clinical phenotypes were collected by retrospective chart review. RESULTS: Patients homozygous for the T allele of the 9545 T/G polymorphism had an increased occurrence of prolonged ICU stay (6.8% for TT genotype versus 2.7% for GG or GT genotype; p = 0.015). Patients homozygous for the T allele also had increased occurrence of low systemic vascular resistance index (62%) compared with the GG and GT genotypes (53%; p = 0.045). Patients homozygous for the T allele had increased serum IL-18 concentrations 24 hours post-surgery (p = 0.018), increased pro-inflammatory tumour necrosis factor alpha concentrations (p = 0.014) and decreased anti-inflammatory serum IL-10 concentrations (p = 0.018) 24 hours post-surgery. CONCLUSIONS: The TT genotype of the IL-18 9545 T/G polymorphism is associated with an increased occurrence of prolonged ICU stay post-surgery and greater post-surgical inflammation. These results may be explained by greater serum IL-18, leading to greater pro-versus anti-inflammatory cytokine expression.

A New Device for Securing Sternal Wires After Median Sternotomy: Biomechanical Study and Retrospective Clinical Assessment.

OBJECTIVE: Morbidity due to sternotomy continues to be a significant clinical problem. Poor approximation of the sternum may lead to complications such as sternal dehiscence, infection, and pain. A device to assist in tensioning and twisting standard steel wires during sternal closure has been developed (TORQ sternal closure device). Manually tightened interrupted wire closures were compared with those tightened and secured with the aid of the device. Performance of the device was assessed clinically. METHODS: Four cardiovascular surgeons performed manual and device-assisted closures on a biofidelic model. Closure force was measured to determine the residual force and its intraoperator variation. A retrospective review of patients treated before and after the introduction of the device was conducted. Predicted and actual outcomes were compared for the two groups (manual closure and device-assisted closure). RESULTS: Biomechanical testing measured a 75% increase in residual closure force (P < 0.001) and a significant reduction in the variability of the closure force (P = 0.045) for device-assisted closures compared with manual closures. In the retrospective study, 3 of 173 manually closed patients had sterile sternal dehiscence and 1 of 173 had a deep sternal wound infection. In the device closure group, 2 of 127 had a sterile sternal dehiscence and no deep sternal wound infections were reported. No other device-related serious adverse events were reported. CONCLUSIONS: Biomechanical data showed stronger, more consistent closure forces with the device. The retrospective data attest to the performance of the device.

Transapical transcatheter aortic valve implantation in humans: initial clinical experience.

BACKGROUND: Aortic valve replacement with cardiopulmonary bypass is currently the treatment of choice for symptomatic aortic stenosis but carries a significant risk of morbidity and mortality, particularly in patients with comorbidities. Recently, percutaneous transfemoral aortic valve implantation has been proposed as a viable alternative in selected patients. We describe our experience with a new, minimally invasive, catheter-based approach to aortic valve implantation via left ventricular apical puncture without cardiopulmonary bypass or sternotomy. METHODS AND RESULTS: A left anterolateral intercostal incision is used to expose the left ventricular apex. Direct needle puncture of the apex allows introduction of a hemostatic sheath into the left ventricle. The valve prosthesis, constructed from a stainless steel stent with an attached trileaflet equine pericardial valve, is crimped onto a valvuloplasty balloon. The prosthetic valve and balloon catheter are passed over a wire into the left ventricle. Positioning within the aortic annulus is confirmed by fluoroscopy, aortography, and echocardiography. Rapid ventricular pacing is used to reduce cardiac output while the balloon is inflated, deploying the prosthesis within the annulus. Transapical aortic valve implantation was successfully performed in 7 patients in whom surgical risk was deemed excessive because of comorbidities. Echocardiographic median aortic valve area increased from 0.7 +/- 0.1 cm2 (interquartile range) to 1.8 +/- 0.8 cm2 (interquartile range). There were no intraprocedural deaths. At a follow up of 87 +/- 56 days, 6 of 7 patients remain alive and well. CONCLUSIONS: This initial experience suggests that transapical aortic valve implantation without cardiopulmonary bypass is feasible in selected patients with aortic stenosis.

Percutaneous aortic valve implantation retrograde from the femoral artery.

BACKGROUND: Percutaneous aortic valve implantation by an antegrade transvenous approach has been described but is problematic. Retrograde prosthetic aortic valve implantation via the femoral artery has potential advantages. Percutaneous prosthetic aortic valve implantation via the femoral arterial approach is described and the initial experience reported. METHODS AND RESULTS: The valve prosthesis is constructed from a stainless steel stent with an attached trileaflet equine pericardial valve and a fabric cuff. After routine aortic balloon valvuloplasty, a 22F or 24F sheath is advanced from the femoral artery to the aorta. A steerable, deflectable catheter facilitates manipulation of the prosthesis around the aortic arch and through the stenotic valve. Rapid ventricular pacing is used to reduce cardiac output while the delivery balloon is inflated to deploy the prosthesis within the annulus. Percutaneous aortic prosthetic valve implantation was attempted in 18 patients (aged 81+/-6 years) in whom surgical risk was deemed excessive because of comorbidities. Iliac arterial injury, seen in the first 2 patients, did not recur after improvement in screening and access site management. Implantation was successful in 14 patients. After successful implantation, the aortic valve area increased from 0.6+/-0.2 to 1.6+/-0.4 cm2. There were no intraprocedural deaths. At follow-up of 75+/-55 days, 16 patients (89%) remained alive. CONCLUSIONS: This initial experience suggests that percutaneous transarterial aortic valve implantation is feasible in selected high-risk patients with satisfactory short-term outcomes.

Six-month outcome of transapical transcatheter aortic valve implantation in the initial seven patients.

BACKGROUND: The current treatment of choice for symptomatic aortic stenosis is aortic valve replacement (AVR) with cardiopulmonary bypass (CPB), but AVR is associated with significant operative morbidity and mortality in elderly patients with multiple co-morbid conditions. We recently reported the first successful aortic valve implantation procedure (AVI) via a mini-thoracotomy and left ventricular apical puncture without cardiopulmonary bypass. We now report 6-month follow-up in our initial seven patients. METHODS: Seven patients (77+/-10 years old) with symptomatic aortic stenosis were deemed to be non-surgical candidates for AVR and not suitable for a transfemoral percutaneous heart valve implantation due to aorto-iliac disease. The predicted 30-day operative mortality was 31+/-23% according to logistic Euroscore. Patients underwent minimally invasive transapical AVI. With the guidance of fluoroscopy and transesophageal echocardiography, balloon predilation was followed by deployment of a 26mm Cribier-Edwardstrade mark valve (Edwards Lifesciences Inc., Irvine, CA) during rapid ventricular pacing to reduce forward flow and cardiac motion. RESULTS: Valve implantation was successful in all seven patients. There were no intra-procedural mortalities or complications. Thirty-day operative mortality was 14%. One patient died at day 12 due to pneumonia. Two patients died from non-cardiac diseases at day 51 and 85. The remaining four patients completed 6-month follow-up. The aortic valve area increased from 0.7+/-0.3 to 1.8+/-0.7 and 1.5+/-0.5cm(2) at 1 and 6 months, respectively. The mean transaortic gradient was reduced from 32+/-8 to 10+/-5 and 11+/-8mmHg at 1 and 6 months, respectively. Following AVI, none or trivial, mild, and moderate aortic regurgitation was observed in 4, 2, and 1 patients, respectively. There were no valve-related complications during the follow-up. CONCLUSION: Aortic valve implantation can successfully be performed via a minimally invasive apical approach without the need for cardiopulmonary bypass. The early results in this initial series are encouraging. This initial experience suggests that the minimally invasive transapical approach is a viable alternative for patients in whom open-heart surgery is not feasible or poses unacceptable risks.

The effects of steroids on the occurrence of postoperative atrial fibrillation after coronary artery bypass grafting surgery: a prospective randomized trial.

OBJECTIVE: Atrial fibrillation remains one of the most common postoperative complications of coronary artery bypass grafting. Despite many clinical studies, there is still no consensus regarding the best prevention strategy for atrial arrhythmia. A randomized, double-blind, placebo-controlled trial was conducted to determine the effect of steroids on the occurrence of atrial fibrillation after elective coronary artery bypass grafting. METHODS: Eighty-eight consecutive patients were prospectively entered in this study. No patient had documented or suspected arrhythmias before surgery. Forty-three patients received 1 g of methylprednisolone before surgery and 4 mg of dexamethasone every 6 hours for 1 day after surgery, and 43 patients received only placebo. The primary end point was the overall occurrence of postoperative atrial fibrillation. RESULTS: Postoperative atrial fibrillation occurred in 9 (21%) of the 43 patients in the steroid group, as compared with 22 (51%) of the 43 patients in the placebo group ( P = .003). Minor postoperative complications occurred in 15 steroid patients (35%) and in 6 patients (14%) receiving placebo ( P = .01). Major complications occurred in 4 patients who received steroids (9%) and in 2 patients (5%) who received placebo ( P = .68; for all complications, P = .05). CONCLUSIONS: Prophylactic short-term steroid administration in patients undergoing coronary artery bypass grafting significantly reduced postoperative atrial fibrillation. In this study, there was no significant difference between the steroid group and the placebo group with regard to the length of hospital stay; however, the steroid group had more complications, which may contribute to prolonged hospitalization.

Performance of bioprostheses and mechanical prostheses in age group 61-70 years.

BACKGROUND AND AIM OF THE STUDY: The performance of bioprostheses (BP) and mechanical prostheses (MP) from valve-related composites of complications and combined major thromboembolism and hemorrhage were considered in order to facilitate decision-making for the patient age group of 61-70 years. METHODS: The aortic valve replacement (AVR) population (BP, n = 619; MP, n = 303) was differentiated by age, concomitant coronary artery bypass, diabetes mellitus, chronic obstructive pulmonary disease (COPD) and preoperative renal failure. The mitral valve replacement (MVR) population (BP, n = 353; MP, n = 312) was differentiated by valve type, age, concomitant coronary artery bypass, ejection fraction, NYHA and preoperative renal failure. RESULTS: Actual freedom from reoperation for AVR was 92.1 +/- 1.5% for BP and 98.7 +/- 6.6% for MP, and for MVR was 74.5 +/- 2.6% for BP and 93.8 +/- 2.2% (12 years) for MP. Actual freedom from major thromboembolism and hemorrhage for AVR was 85.1 +/- 1.7% for BP and 76.9 +/- 3.6% for MP, and for MVR was 82.7 +/- 2.4% for BP and 76.7 +/- 3.8% (12 years) for MP. Linearized rates were undifferentiated for major thromboembolism. The hemorrhage rate for AVR-BP was 0.55%/pt-yr and for AVR-MP was 2.3%/pt-yr (p < 0.0001); for MVR-BP, the rate was 0.69%/pt-yr and for MVR-MP was 1.85%/pt-yr (p = 0.0011). The only predictor of AVR reoperation was age, and predictors for MVR reoperation were prosthesis type and follow up NYHA class. Predictors of AVR major thromboembolism and hemorrhage were prosthesis type, age, diabetes mellitus and COPD. There were no predictors of MVR major thromboembolism and hemorrhage. CONCLUSION: For the age group of 61-70 years, MP are recommended for MVR to protect from BP reoperation, whilst for AVR BP are recommended to protect from anticoagulant hemorrhage. Freedom from reoperation for AVR was undifferentiated for BP and MP at 12-15 years.

Traction injury during minimally invasive harvesting of the saphenous vein is associated with impaired endothelial function.

OBJECTIVE: Many methods of minimally invasive surgical harvesting of the great saphenous vein have been developed because of the morbidity related to the long skin incision after traditional (open) great saphenous vein harvesting. One such method involves the use of multiple small incisions separated by 10- to 15-cm skin bridges through which the saphenous vein is harvested. We hypothesized that this method of saphenous vein harvesting might subject the saphenous vein to considerable traction forces, resulting in impaired endothelial cell function. METHODS: Four-millimeter great saphenous vein segments were obtained from patients undergoing elective coronary artery bypass graft surgery. Group A (minimally invasive surgery) consisted of 23 rings from 20 patients (age, 65.8 +/- 11.1 years, mean +/- SD). Group B (open harvesting) consisted of 33 rings from 8 patients (age, 69.8 +/- 8.6 years). All great saphenous vein segments were undistended and were used within 24 hours of harvesting. Isometric tension experiments were performed on each ring of the great saphenous vein by using a force-displacement transducer to measure the force of contraction in grams. Measurements included developed force after exposure to high-potassium depolarizing solution and 50 micromol/L phenylephrine and decrease in force of contraction (relaxation) after exposure to 1 and 10 micromol/L acetylcholine. RESULTS: There were no differences between the minimally invasive surgery and open harvesting groups in their responses to high-potassium depolarizing solution or phenylephrine: high-potassium depolarizing solution, contractions of 4.26 +/- 0.72 g (mean +/- SEM) and 3.95 +/- 0.38 g, respectively (P =.70); phenylephrine, contractions of 3.49 +/- 0.63 g and 2.73 +/- 0.39 g, respectively (P =.41). There was no net relaxation in segments from the minimally invasive surgery group after exposure to 1.0 or 10 micromol/L acetylcholine. In contrast, rings from the open harvesting group demonstrated relaxation of -0.41 +/- 0.07 g and -0.32 +/- 0.09 g after exposure to 1.0 and 10 micromol/L acetylcholine, respectively. CONCLUSIONS: In undistended saphenous vein segments isolated from patients undergoing minimally invasive surgical and open techniques of harvesting, there was no acetylcholine-mediated endothelium-dependent relaxation in the minimally invasive surgery group. Therefore harvesting of the great saphenous vein through multiple small incisions might result in endothelial dysfunction, possibly caused by traction injury.

Prolonged QTc affects short-term and long-term outcomes in patients with normal left ventricular function undergoing cardiac surgery.

OBJECTIVE: Although it is known that preoperative decreased left ventricular ejection fraction (LVEF) is a risk for morbidity and mortality after cardiac surgery, there are no reliable markers of risk in patients with preserved LVEF. This study examines whether a prolonged QTc interval is associated with adverse outcomes in patients with preoperative LVEF greater than 40% undergoing cardiac surgery. METHODS: A retrospective chart review of patients who had cardiac surgery at St. Paul's Hospital in Vancouver, Canada, between 2004 and 2009, who had a preoperative LVEF greater than 40%, was undertaken. We tested for association of preoperative prolonged QTc interval with mortality and morbidity using unadjusted and adjusted analyses. RESULTS: Five-hundred and fifty-five patients with a preoperative LVEF greater than 40% were included in the study; 496 (89.4%) had cardiopulmonary bypass and the remainder were off pump. Preoperative prolonged QTc was associated with increased mortality at 30 days (P < .01), 90 days (P < .01), and 8 years (P < .01), and these results remained significant after adjusting for the clinical variables significantly associated with mortality (8-year odds ratio, 2.42; 95% confidence interval, 1.34-4.34; P = .003). Similar results were found when the analysis was restricted to the more homogeneous group of patients undergoing on-pump coronary artery bypass (CABG, n = 408). Prolonged QTc was also associated with prolonged intensive care unit stay (P = .02), prolonged hospital stay (P < .01), development of atrial arrhythmias (P = .02), and low cardiac output syndrome (on-pump CABG, P = .02). CONCLUSIONS: In patients undergoing cardiac surgery and a preoperative LVEF greater than 40%, a prolonged QTc interval is associated with increased short-term and long-term mortality and increased perioperative morbidity, and therefore should be considered when assessing risk preoperatively.

Transapical transcatheter aortic valve-in-valve implantation: clinical and hemodynamic outcomes beyond 2 years.

OBJECTIVE: The feasibility of transapical valve-in-valve aortic valve implantation into a failed aortic surgical bioprosthesis has been confirmed. The purpose of the present study was to investigate the clinical and hemodynamic outcomes more than 2 years after transapical valve-in-valve aortic valve implantation. METHODS: From April 2007 to May 2010, 8 consecutive patients underwent transapical valve-in-valve aortic valve implantation of either 23- or 26-mm Edwards-SAPIEN balloon-expandable bioprostheses into failed surgical tissue valves (21- to 25-mm valves). Clinical and echocardiographic follow-up was performed in all patients. The mean follow-up duration was 27.8 ± 15.7 months (range, 18-55 months). RESULTS: Transapical valve-in-valve aortic valve implantation was successful in all patients (mean age, 84.1 ± 1.6 years). The predicted operative mortality was 42.1% ± 15.7% by logistic European System for Cardiac Operative Risk Evaluation and 14.4% ± 9.6% using the Society of Thoracic Surgeons risk calculator. The observed 30-day mortality was 12.5%. No strokes or valve embolization/migrations occurred. The mean hospital stay was 9.0 ± 9.1 days. The New York Heart Association class decreased from preoperative class III-IV to postoperative class I in 6 of 7 survivors. The 2-year survival was 87.5%. No late mortality occurred during the follow-up period. The echocardiographic results at 1 to 4 years of follow-up demonstrated stable valve position and function in all patients. The transaortic valve pressure gradients after valve-in-valve aortic valve implantation were greater than 20 mm Hg and less than 15 mm Hg in patients with 21- or 23-mm and 25-mm surgical valves, respectively. CONCLUSIONS: Transapical valve-in-valve aortic valve implantation provides good clinical outcomes and stable valve function beyond 2 years of follow-up. The best hemodynamic and clinical outcomes can be achieved in the patients with a surgical valve size of 25 mm or greater. Valve-in-valve aortic valve implantation could become a viable approach for selected high-risk patients with failed surgical bioprostheses.

Transcatheter aortic valve implantation: a Canadian Cardiovascular Society position statement.

Patients with severe symptomatic aortic stenosis have a poor prognosis with medical management alone, and balloon aortic valvuloplasty has failed to provide durable clinical benefit. Open surgical replacement of the aortic valve can improve symptoms and survival. Recently, transcatheter aortic valve implantation (TAVI) has been demonstrated to improve survival, quality of life, and functional status in nonoperable patients and to be a viable option for patients in whom the risk of open surgical morbidity or mortality is high. This Canadian Cardiovascular Society position statement represents the consensus of a representative group of cardiologists and cardiac surgeons as to the current, but evolving, role of this less-invasive new therapy. Specific recommendations are provided for selection of patients for TAVI vs surgical aortic valve replacement for native valves and for bioprostheses, approaches to patient evaluation for TAVI, appropriate constitution of multidisciplinary teams involved in performing TAVI, essential facilities that are needed to perform TAVI safely and effectively, and training/qualifications for TAVI operators. Cost considerations, complication rates, and the quality of the available evidence are also discussed. It is hoped that this consensus document will prove to be a useful resource for health professionals, institutions, departments, and decision-making bodies dealing with this important and rapidly evolving therapy.

Pathology of transcatheter valve therapy.

OBJECTIVES: This study sought to report on the pathology of transcatheter aortic valves explanted at early and late time points after transcatheter aortic valve implantation. BACKGROUND: Information on pathological findings following transcatheter aortic valve implantation is scarce, particularly late after transcatheter aortic valve implantation. METHODS: This study included 20 patients (13 men, median age 80 years [interquartile range: 72 to 84] years) with previous transcatheter aortic valve implantation with a valve explanted at autopsy (n = 17) or surgery (n = 3) up to 30 months after implantation (10 transapical and 10 transfemoral procedures). RESULTS: Structural valve degeneration was not seen, although fibrous tissue ingrowth was observed at later time points with minimal effects on cusp mobility in 1 case. Minor alterations in valve configuration or placement were observed in up to 50% of cases, but they were not accompanied by substantial changes in valve function or reliably associated with chest compressions. Vascular or myocardial injury was common, especially within 30 days of transcatheter aortic valve implantation (about 69%), with the latter associated with left coronary ostial occlusion by calcified native aortic valve tissue in 2 cases. Mild to severe myocardial amyloidosis was present in nearly 33% of cases and likely played a role in the poor outcome of 3 patients. Endocarditis, migration of the valve, and embolization during the procedure led to surgical valve removal. CONCLUSIONS: Structural degeneration was not seen and minor alterations of valve configuration or placement did not affect valve function and were not reliably caused by chest compressions. Vascular or myocardial injury is very common early after transcatheter aortic valve implantation and myocardial amyloidosis represents a relatively frequent potentially significant comorbid condition.

Long-term outcomes after transcatheter aortic valve implantation: insights on prognostic factors and valve durability from the Canadian multicenter experience.

OBJECTIVES: This study sought to evaluate the long-term outcomes after transcatheter aortic valve implantation (TAVI) in the Multicenter Canadian Experience study, with special focus on the causes and predictors of late mortality and valve durability. BACKGROUND: Very few data exist on the long-term outcomes associated with TAVI. METHODS: This was a multicenter study including 339 patients considered to be nonoperable or at very high surgical risk (mean age: 81 ± 8 years; Society of Thoracic Surgeons score: 9.8 ± 6.4%) who underwent TAVI with a balloon-expandable Edwards valve (transfemoral: 48%, transapical: 52%). Follow-up was available in 99% of the patients, and serial echocardiographic exams were evaluated in a central echocardiography core laboratory. RESULTS: At a mean follow-up of 42 ± 15 months 188 patients (55.5%) had died. The causes of late death (152 patients) were noncardiac (59.2%), cardiac (23.0%), and unknown (17.8%). The predictors of late mortality were chronic obstructive pulmonary disease (hazard ratio [HR]: 2.18, 95% confidence interval [CI]: 1.53 to 3.11), chronic kidney disease (HR: 1.08 for each decrease of 10 ml/min in estimated glomerular filtration rate, 95% CI: 1.01 to 1.19), chronic atrial fibrillation (HR: 1.44, 95% CI: 1.02 to 2.03), and frailty (HR: 1.52, 95% CI: 1.07 to 2.17). A mild nonclinically significant decrease in valve area occurred at 2-year follow-up (p < 0.01), but no further reduction in valve area was observed up to 4-year follow-up. No changes in residual aortic regurgitation and no cases of structural valve failure were observed during the follow-up period. CONCLUSIONS: Approximately one-half of the patients who underwent TAVI because of a high or prohibitive surgical risk profile had died at a mean follow-up of 3.5 years. Late mortality was due to noncardiac comorbidities in more than one-half of patients. No clinically significant deterioration in valve function was observed throughout the follow-up period.

Transcatheter transapical mitral valve-in-valve implantations for a failed bioprosthesis: a case series.

OBJECTIVES: Mitral valve replacement with bioprosthetic valves is becoming more common. The incidence of structural valve deterioration and the need for reoperative mitral surgery are expected to increase. The operative mortality and morbidity associated with redo mitral surgery remains high. Transapical transcatheter mitral valve-in-valve implantation might offer an alternate and safer approach for high-risk patients. METHODS: From July 2007 to April 2010, 11 patients with symptomatic mitral prosthetic valve dysfunction underwent transapical transapical transcatheter mitral valve-in-valve implantation in our institution. Data were collected and entered into a database prospectively. The mean age was 81 ± 5 years, with 64% being female. The mean Society of Thoracic Surgeons risk score was 16.1% ± 5.8%. RESULTS: All patients had successful transapical transcatheter mitral valve-in-valve implantation with no 30-day mortality. One patient died 45 days after surgical intervention from respiratory failure, and 1 patient died on day 135. All other patients were alive and in New York Heart Association class I/II at a median follow-up of 357 days. The median postprocedural transvalvular gradient was 7 mm Hg, and minimal transvalvular or paravalvular regurgitation was seen. CONCLUSIONS: Transcatheter transapical valve-in-valve implantations into a failed mitral bioprosthesis is technically feasible with acceptable results. It might be a viable approach for selected high-risk patients.