A. Mazine

Long-term outcomes after elective isolated mechanical aortic valve replacement in young adults

OBJECTIVES The aim of this study was to determine long-term survival and clinical outcomes after elective isolated mechanical aortic valve replacement in young adults. METHODS A clinical observational study was conducted in a cohort of 450 consecutive adults less than 65 years of age who had undergone elective isolated mechanical aortic valve replacement (AVR) between 1997 and 2006. Patients who had undergone previous cardiac surgery, and those undergoing concomitant procedures or urgent surgery were excluded. Follow-up was 93.3% complete with a mean follow-up of 9.1±3.5 years. The primary end point was survival. Life table analyses were used to determine age- and gender-matched general population survival. Secondary end points were reoperation and valve-related complications. RESULTS Overall actuarial survival at 1, 5, and 10 years was 98%±1%, 95%±1%, and 87%±1%, respectively, which was lower than expected in the age- and gender-matched general population in Quebec. Actuarial freedom from prosthetic valve dysfunction was 99%±0.4%, 95%±1%, and 91%±1% at 1, 5, and 10 years, respectively. Actuarial freedom from valve reintervention was 98%±1%, 96%±1%, and 94%±1% at 1, 5 and 10 years, respectively. Actuarial survival free from reoperation at 10 years was 82%±2%. Actuarial freedom from major hemorrhage was 98%±1%, 96%±1%, and 90%±2% at 1, 5, and 10 years, respectively. CONCLUSIONS In young adults undergoing elective isolated mechanical AVR, survival remains suboptimal compared with an age- and gender-matched general population. Furthermore, there is a low but constant hazard of prosthetic valve reintervention after mechanical AVR.

Sutureless Aortic Valve Replacement: A Canadian Multicentre Study

BACKGROUND Sutureless aortic valve replacement (AVR) has recently been introduced as an alternative to standard AVR in elderly high-risk surgical patients. The purpose of this study was to report the early Canadian experience with sutureless AVR. METHODS A Canadian multicenter study included 215 consecutive patients from 6 centres who underwent sutureless AVR using the Perceval S bioprosthesis (Sorin Group, Saluggia, Italy) between June 2011 and May 2013. Perioperative clinical and echocardiographic outcomes were assessed in all patients. RESULTS Mean age was 79 ± 6 years, and 116 patients (54%) were women. Concomitant procedures included coronary artery bypass grafting in 86 patients (40%), multiple valve procedures in 24 (11%) patients, and septal myectomy in 9 (4%) patients. A full sternotomy was used in 173 cases (80%), a minithoracotomy in 23 (11%) cases, and a partial sternotomy in 19 (9%) cases. Nineteen cases (9%) were redo procedures. For isolated AVR, mean aortic cross-clamp time was 41 ± 12 minutes. In-hospital mortality occurred in 9 patients (4%). No postoperative valve migration was reported. A total of 37 patients (17%) underwent postoperative implantation of a permanent pacemaker, including 20 patients (9%) who had complete atrioventricular block. Postoperative stroke occurred in 7 patients (3%). Echocardiographic evaluation demonstrated well-seated valves with no significant (2+) valvular or paravalvular aortic insufficiency and a mean aortic gradient of 13 ± 6 mm Hg. CONCLUSIONS Sutureless AVR using the Perceval S prosthesis is safe and reproducible and results in short operative times. Echocardiographic results are encouraging, with low gradients and no paravalvular aortic insufficiency. However, in this series, sutureless AVR was associated with a high risk of permanent pacemaker implantation.

Expanding the indication for sutureless aortic valve replacement to patients with mitral disease

OBJECTIVES To review our experience with sutureless aortic valve replacement (AVR) in the setting of concomitant mitral valve (MV) surgery and discuss the technical considerations. METHODS Between January 2012 and March 2013, 10 patients underwent sutureless AVR with the Perceval prosthesis in the setting of concomitant mitral disease. Five patients underwent MV repair, 4 underwent MV replacement, and 1 had a previously implanted mechanical mitral prosthesis. RESULTS The median age was 79 years and 7 patients (70%) were male. Median logistic EuroSCORE II was 6.2%. All valves were successfully implanted with no 30-day mortality. There was no residual aortic paravalvular leak. Two patients had from third-degree atrioventricular block requiring permanent pacemaker implantation. At a mean follow-up of 8±4 months (range, 2-16 months), the overall survival was 80% with 2 non-valve-related deaths and the mean transaortic gradient and aortic valve area had improved to 11.1±4.6 mm Hg and 1.5±0.3 cm2, respectively. There was no evidence of mitral dysfunction in any patient. CONCLUSIONS In our experience, sutureless AVR in the setting of concomitant mitral surgery is a feasible and reproducible procedure. Elderly patients undergoing multiple valve surgery present a higher operative risk, therefore extending the indication for sutureless AVR to patients with concomitant mitral disease could greatly benefit this specific population.

Pericardiectomy for Constrictive Pericarditis: 20 Years of Experience at the Montreal Heart Institute

BACKGROUND The aim of this study was to evaluate our single-center experience with pericardiectomy for constrictive pericarditis. The main objectives of our analysis were long-term survival, clinical outcome, and identification of risk factors. METHODS Over a 20-year period, 99 consecutive patients underwent pericardiectomy at the Montreal Heart Institute. The indications for operation were idiopathic pericarditis (61%), postsurgical (13%), infectious (15%), postirradiation (2%), and miscellaneous (9%). Associated procedures were performed in 36% of cases. The duration of symptoms was longer than 6 months in 53% of cases, and two thirds of patients were in New York Heart Association class III or IV. RESULTS Hospital mortality was 9% in the whole series and 7.9% in case of isolated pericardiectomy. The patients operated on within 6 months after the onset of symptoms showed a lower risk of mortality. Conversely, preoperative hepatomegaly and concomitant valvular operation were associated with significantly higher mortality on both univariate and multivariate analysis. In cases of isolated pericardiectomy, the outcome was mainly conditioned by associated comorbidities. The long-term survival was satisfactory, and the functional status at follow-up was improved in most cases. CONCLUSIONS The clinical outcome of pericardiectomy for constrictive pericarditis is still marked by high operative mortality. Nevertheless, surgical treatment is able to improve the functional class in the majority of late survivors. Preoperative clinical conditions and associated comorbidities are crucial in predicting the risk of mortality, and early operation seems to be the most appropriate choice. The most suitable surgical strategy in cases of associated valvular operation remains to be determined.

Long-term results after surgical treatment of paravalvular leak in the aortic and mitral position.

OBJECTIVES The aim of this study was to determine immediate results and long-term outcomes after surgical management of paravalvular leak (PVL). METHODS Between 1995 and 2012, a total of 190 patients underwent primary surgical repair (n = 142) or valve replacement (n = 48) for a PVL at our institution. The PVL was mild in 6 (3%) patients, moderate in 85 (45%), moderate to severe in 84 (44%), and severe in 15 (8%). Among these, 120 (63%) had PVL in the mitral position, 63 (33%) had PVL in the aortic position, and 7 (4%) had PVL in both valves. Mean follow-up was 5.3 ± 4.6 years. RESULTS Mean age at surgery was 63 ± 12 years (64% men). Operative mortality occurred in 13 (7%) patients (10 [8%] in mitral; 2 [3%] in aortic; and 1 [14%] in double valve procedures). Survival at 1, 5, and 10 years was 85% ± 3%, 73% ± 4%, and 56% ± 5%, respectively. The cumulative incidence of PVL recurrence was 3% ± 1%, 14% ± 3%, and 32% ± 6%, at 1, 5, and 10 years, respectively. The number of previous surgeries was a predictor of survival and PVL recurrence. Freedom from New York Heart Association class ≥III was 96% ± 2%, 82% ± 4%, and 58% ± 6%, at 1, 5, and 10 years, respectively. The freedom from rehospitalization for heart failure was 92% ± 2%, 83% ± 4%, and 67% ± 6%, at 1, 5, and 10 years. CONCLUSIONS Surgical treatment of PVL resulted in acceptable outcomes. Nevertheless, the continued risk of PVL recurrence is higher in patients who have had multiple previous surgeries. More studies are needed to compare these results with the transcatheter PVL reduction technique.

Twenty-year experience with the CarboMedics mechanical valve prosthesis.

BACKGROUND The CarboMedics mechanical prosthesis (CarboMedics Inc, Austin, TX) has been used for mitral and aortic valve replacement for more than 20 years in our institution. This study describes the long-term survival of patients with this prosthesis as well as the valve-related events. METHODS Between June 1988 and May 2010, 3,297 patients underwent either single aortic valve replacement (AVR) (2,242 patients) or mitral valve replacement (MVR) (1,055 patients) with the CarboMedics mechanical valve prosthesis. They were followed annually for valve-related complications at the Montreal Heart Institute valve clinic. RESULTS Operative mortality was 4% with AVR and 7% with MVR. Total follow-up was 23,671 patient-years (range, 1 month to 21 years; average, 7.5 ± 5.3 years). At 20 years, patient freedom from late mortality was 43.2% in the AVR group and 40.9% in the MVR group. Freedom from valve-related mortality was 78.3% for AVR and 74.6% for MVR. Freedom from thromboembolic event was 91.6% for AVR and 88.5% for MVR. Freedom from reoperation was 89.2% for AVR and 80.3% for MVR. Freedom from bleeding event was 89.5% for AVR and 88% for MVR. Freedom from endocarditis was 97.3% for both AVR and MVR. Freedom from valve thrombosis was 98.9% for AVR and 91.4% for MVR. There was no structural valve failure in our cohort. CONCLUSIONS The CarboMedics valve is an effective and durable mechanical valve prosthesis with a low event rate and no structural failure at 20 years.

Transcatheter Aortic Valve Implantation by the Left Axillary Approach: A Single-Center Experience

BACKGROUND Transcatheter aortic valve implantation (TAVI) is an accepted alternative treatment for severe symptomatic aortic stenosis in high-risk and inoperable patients. Femoral or transapical accesses are commonly used. We report our initial clinical experience with TAVI using the left-axillary artery approach. METHODS A single-center, retrospective study of patients undergoing transaxillary TAVI between January 2010 and December 2012 was performed. Procedural success was defined as successful device implantation with reduction in the mean aortic gradient and without need for conversion to open-heart surgery. Short-term echocardiographic follow-up was obtained in all patients. RESULTS A total of 18 consecutive patients with severe aortic stenosis who were not candidates for surgical replacement underwent transaxillary TAVI. Mean age was 81.1±7.3 years and 14 patients (78%) were male. Median logistic European System for Cardiac Operative Risk Evaluation was 8.5% (range, 1.5% to 54.1%). Procedural success was obtained in 17 out of 18 patients (94%). There was no in-hospital or 30-day mortality. One major bleeding complication in the form of an upper gastrointestinal bleeding was observed. No stroke or major vascular complication was reported. Postoperative implantation of a permanent pacemaker was performed in 7 patients (39%). At a mean follow-up of 326±213 days, mean aortic gradient was 10.8±4.8 mm Hg. Mean aortic valve area was 1.7±0.4 cm2 and aortic insufficiency grade was mild or less in all but 1 patient, who showed moderate regurgitation. CONCLUSIONS The transaxillary approach for TAVI is associated with high procedural success and low rates of stroke, vascular, or bleeding complications. This approach is an appealing alternative to the commonly used transfemoral and transapical TAVI.

Differences and similarities in risk factors for postoperative acute kidney injury between younger and older adults undergoing cardiac surgery

Objectives Acute kidney injury is a frequent complication after cardiac surgery. The purpose of this study was to assess the risk factors for acute kidney injury in patients ≤60 years of age undergoing cardiac surgery and to compare these risk factors with those identified in patients ≥65 years of age. Methods From 2010 to 2012, 1253 patients ≤60 years (mean age 52 ± 9 years) and 2488 patients ≥65 years (mean age 74 ± 6 years) underwent cardiac surgery. Linear regression models using least absolute shrinkage and selection operator methods and mixed effects linear regression models were used to assess factors associated with maximum postoperative increase in serum creatinine in these two cohorts. Results In both age groups, the following variables were associated independently with greater degrees of postoperative increase in serum creatinine on multivariable analysis: greater body mass index, peripheral vascular disease, preoperative use of diuretics, lower preoperative hemoglobin, preoperative intra‐aortic balloon pump, urgent or emergent status, long cardiopulmonary bypass time, and hemofiltration. In younger patients, a greater increase in serum creatinine was associated with diabetes, and previous cardiac surgery, whereas female sex was associated with a lower degree of increase in serum creatinine. In older patients, a greater increase in serum creatinine was associated with age, hypertension, smoking, and lower left ventricular left ejection fraction. Operation type and coronary artery disease had a different impact on postoperative creatinine increase between younger and older patients. Conclusions This study identified both common and distinct risk factors associated with postoperative increase in serum creatinine between patients ≤60 years and those ≥65 years undergoing cardiac surgery. Importantly, all potentially modifiable risk factors were present in both groups.

Knowledge, attitudes, and practice preferences of Canadian cardiac surgeons toward the management of acute type A aortic dissection

OBJECTIVES The complexity of surgical treatment for acute type A dissection contributes to the variability in patient management. This study was designed to elucidate the contemporary practice preferences of cardiac surgeons regarding different phases of management of acute type A aortic dissection. METHODS A 34-item questionnaire was distributed to all Canadian adult cardiac surgeons addressing the preoperative, intraoperative, and postoperative management of acute type A dissection. A total of 100 responses were obtained (82% of active surgeons in Canada). Outcomes were compared between high- and low-volume aortic surgeons. RESULTS Seventy-six percent of respondents favored axillary artery cannulation. High-volume surgeons (>150 cases) were more likely to indicate a target lowest nasopharyngeal temperature more than 20 °C (53% vs 25%, P = .02). The majority of surgeons (65%) recommended using selective antegrade cerebral perfusion, with a significantly greater proportion for higher-volume aortic surgeons (P = .03). In addition, high-volume aortic surgeons were more likely to recommend aortic root replacement at smaller diameters (73% vs 55%, P = .02), to recommend more extensive distal aortic resection with routine open hemiarch anastomosis (85% vs 65%, P = .04), and to more commonly perform total arch reconstruction when needed (93% vs 77%, P = .04). In the follow-up period, frequency of serial imaging of the residual aorta was significantly higher for high-volume aortic surgeons (P = .04). CONCLUSIONS This study identified some commonalities in practice preferences among Canadian cardiac surgeons for the management of acute type A aortic dissection. However, it also highlighted significant differences in temperature management, cerebral protection strategies, and extent of resection between high-volume and low-volume aortic surgeons.

Successful Repair of a Bicuspid Aortic Valve With Anomalous Chordal Attachment to the Aortic Wall

The congenitally bicuspid aortic valve with anomalous chordal attachment of the fused cusp to the aortic wall is a rare and unappreciated cause of aortic insufficiency. We report the case of a 43-year-old male patient who presented with severe aortic insufficiency caused by this anomaly and in whom surgical aortic valve repair was successfully performed. To our knowledge, this is the first report to describe the successful surgical repair of this rare variant of bicuspid aortic valve.