Long-term outcomes of the Ross procedure in adults with severe aortic stenosis: single-centre experience with 20 years of follow-up.

OBJECTIVES: The optimal prosthesis option for aortic valve replacement in adult patients<60 years of age with severe aortic stenosis (AS) remains controversial. The objective was to determine the long-term outcomes of the Ross procedure in this population. METHODS: Between 1990 and 2013, 276 patients aged 18 years and above (mean 40.3±10.6) underwent an elective Ross procedure. Among them, 221 patients had predominant severe AS; these patients form the study group. The Ross procedure was performed either by aortic root replacement (n=190; 86%) or the subcoronary technique (n=31; 14%). There were 169 patients with bicuspid valves and 33 redo operations including previous aortic valve repair (n=6) and replacement (n=9) for severe AS. Demographic, preoperative, postoperative and longitudinal clinical and echocardiographic data were collected prospectively. The median and mean follow-up were 11.4 years (range: 1-20.1 years) and 10.1±5.9 years, respectively. The follow-up was complete in all patients. Kaplan-Meier actuarial survival analysis was performed to assess long-term survival, freedom from reoperation for autograft and/or homograft failure and freedom from autograft valve insufficiency. Cox regression risk analysis was performed to identify factors associated with autograft or homograft reoperations. RESULTS: The perioperative mortality rate was 0.9% (n=2). The incidence rate of early reoperation for bleeding was 5.9%. The actuarial survival rate at 10 and 15 years following surgery was 92.1 and 90.5%, respectively. Ross-related reoperations occurred in 21 patients during follow-up: autograft dysfunction (n=9), homograft dysfunction (n=6) and both (n=6). The rate of freedom from Ross-related reoperation was 94.7 and 87.7% at 10 and 15 years, respectively. The rate of freedom from reoperation for autograft failure was 97.6 and 91.5%, the rate of freedom from reoperation for homograft failure was 95.7 and 90.8%, and the rate of freedom from moderate or severe autograft regurgitation was 94.1 and 85.6% at 10 and 15 years, respectively. CONCLUSIONS: Compared with available aortic bioprosthetic alternatives in young adults with severe AS, the Ross procedure provides an excellent long-term option for patients with predominant severe AS who seek a durable operation without anticoagulation.

Long-term clinical and echocardiographic follow-up of the Freestyle stentless aortic bioprosthesis.

BACKGROUND: Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ≤18 years. METHODS AND RESULTS: Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2 ± 8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1 ± 4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age (P=0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years (P=0.001) and dyslipidemia (P=0.02). CONCLUSIONS: Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

Permanent pacemaker implantation following isolated aortic valve replacement in a large cohort of elderly patients with severe aortic stenosis.

OBJECTIVES: To assess the incidence of conduction disturbances leading to permanent pacemaker implantation (PPI) following isolated aortic valve replacement (AVR) in a large cohort of elderly patients with severe symptomatic aortic stenosis, and to determine the predictive factors and prognostic value of PPI following AVR in such patients. METHODS: A total of 780 consecutive elderly patients (age 77 ± 4 years, logistic EuroSCORE 10.4 ± 8.5%, STS score 3.5 ± 1.5%) with severe aortic stenosis and no previous pacemaker were analysed. MAIN OUTCOME MEASURES: The incidence, clinical indications, timing and predictive factors of PPI within 30 days after AVR and their prognostic value were evaluated. RESULTS: Baseline ECG showed the presence of conduction abnormalities in 37.1% of the patients. Twenty-five patients (3.2%) needed PPI during the index hospitalisation due to the occurrence of complete atrioventricular block (2.6%) or severe bradycardia (0.6%). The presence of preprocedural left bundle branch block (OR 4.65, 95% CI 1.62 to 13.36, p = 0.004) or right bundle branch block (OR 4.21, 95% CI 1.47 to 12.03, p = 0.007) predicted the need for PPI after AVR. The need for PPI was associated with a longer hospital stay (p<0.0001). Thirty-day mortality rates were similar between patients with and without PPI (4% vs 3.2%, p = 0.56). Survival rate at 5-year follow-up was 75%, with no differences between patients with and without PPI (p = 0.12). CONCLUSIONS: The need for PPI following isolated AVR in elderly patients with severe symptomatic aortic stenosis was low. Pre-existing bundle branch block predicted the need for PPI. PPI determined a longer hospital stay, but had no effect on acute and long-term mortality.

Medtronic Mosaic porcine bioprosthesis: assessment of 12-year performance.

BACKGROUND: The Mosaic porcine bioprosthesis (Medtronic, Inc, Minneapolis, Minn) was approved in 2000 by the US Food and Drug Administration. Clinical performance was evaluated in 6 centers. METHODS: From 1994 to 2000, 797 patients (mean age 69 years) had aortic valve replacement (AVR) and 232 (mean 67 years) had mitral valve replacement (MVR). Concomitant coronary artery bypass grafting was performed with aortic valve replacement (45.4%) and mitral valve replacement (43.5%). Mean follow-ups were 7.5 years for aortic position and 7.3 years for mitral position. RESULTS: Early mortalities were 2.8% for AVR and 3.0% for MVR. Late mortalities were 4.2%/patient-year for AVR and 5.1%/patient-year for MVR. Overall 12-year survivals were 55.8% ± 3.7% for AVR and 43.9% ± 7.4% for MVR. Twelve-year freedoms from valve-related mortality were 87.1% ± 3.1% for AVR and 82.5% ± 7.7% for MVR. Twelve-year freedoms from reoperation were 84.0% ± 3.3% for AVR and 82.5% ± 7.5% for MVR. Freedoms from structural valve deterioration (SVD) by explant reoperation at 12 years for AVR were 93.3% ± 2.6% for patients at least 60 years old and 75.9% ± 9.3% for patients younger than 60 years. Freedoms from SVD by explant reoperation at 10 years for MVR were 95.3% ± 7.8% for patients at least 70 years old and 84.0% ± 9.3% for patients younger than 70 years. Hemodynamic performance data at 1 year for AVR (sizes 21-27 mm) were mean systolic gradient range 13.7 ± 4.8 to 10.3 ± 3.2 mm Hg and effective orifice area range 1.5 ± 0.3 to 2.5 ± 0.4 cm(2). For MVR (sizes 25-31 mm), data were mean diastolic gradient range 6.7 ± 1.7 to 3.7 ± 0.9 mm Hg and effective orifice area range 1.9 ± 0.3 to 2.4 ± 0.6 cm(2). CONCLUSIONS: Overall performance of Mosaic porcine bioprosthesis to 12 years is satisfactory. Freedoms from SVD by explant reoperation were most satisfactory for aortic position in patients at least 60 years old and mitral position in patients at least 70 years old. Overall actuarial freedom from SVD by explant reoperation is encouraging for patients with MVR.

Freedom from structural valve deterioration among patients aged < or = 60 years undergoing Freestyle stentless aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: Certain theoretical arguments suggest that a stentless bioprosthetic valve may be less subject to calcification and degeneration compared to an equivalent stented bioprosthesis. The study aim was to define the long-term clinical outcomes, including freedom from structural valve deterioration (SVD), among relatively younger patients after aortic valve replacement (AVR) with the Freestyle aortic bioprosthesis. METHODS: A total of 725 patients at eight study sites underwent AVR with the Freestyle stentless aortic bioprosthesis. Of these patients, 57 (7.9%) were aged < or = 60 years at the time of surgery. All clinical data were recorded prospectively. RESULTS: The total follow up for the group was 4,900 patient-years; the mean follow up per patient was 6.8 +/- 3.6 years; median 7.2 years; range: 0 to 13.3 years). Survival at 12 years was 65.0 +/- 11.6% for patients aged < or = 60 years at implant, and 33.1 +/- 5.3% for those aged > or = 61 years. Freedom from cardiac death was 94.6 +/- 6.6% and 70.7 +/- 7.5%, respectively. Freedom from SVD at 12 years was 92.4 +/- 8.0% for patients aged < or = 60 years at implant, and 92.3 +/- 5.0% for those aged > or = 61 years (p = 0.58). There was no significant difference in freedom from reoperation at 12 years between the younger and older age groups (p = 0.16). CONCLUSION: The Freestyle stentless aortic bioprosthesis was associated with excellent clinical outcomes through 12 years of follow up. Freedom from cardiac death was excellent. Measures of bioprosthesis durability remained outstanding through 12 years, with no difference in freedom from SVD or from reoperation between patients aged < or = 60 years and those aged > or = 61 years at the time of implant. Inasmuch as valve durability may influence decisions between a tissue and a mechanical valve in younger patients, these data help to support use of the Freestyle valve in patients aged < or = 60 years.

Long-term impact of diabetes and its comorbidities in patients undergoing isolated primary coronary artery bypass graft surgery.

BACKGROUND: The objective of this study was to identify the impact of diabetes and related comorbidities, namely chronic renal failure, peripheral vascular disease, and low ejection fraction (<35%), on long-term survival of patients undergoing coronary artery bypass graft surgery. METHODS AND RESULTS: A unicenter study was conducted on 9125 survivors of isolated coronary artery bypass graft surgery between 1992 and 2002. There were 6581 nondiabetic patients and 2544 diabetics, including 1809 patients with noninsulin-dependent diabetes mellitus and 735 patients with insulin-dependent diabetes mellitus. Cardiac-specific survival at 5 and 10 years was lower in insulin-dependent diabetes mellitus compared with both nondiabetic mellitus patients and patients with noninsulin-dependent diabetes mellitus (P<0.0001). However, freedom from cardiac-related death was similar for patients with noninsulin-dependent diabetes mellitus and nondiabetes mellitus patients up to 6 years (P=0 0.08) after surgery and was significantly lower thereafter (P=0.004). Cardiac-specific survival after coronary artery bypass graft surgery in patients with one or more comorbidities was comparable (P=0.4) for both nondiabetes mellitus patients and patients with noninsulin-dependent diabetes mellitus, but was significantly lower for those requiring insulin therapy (P<0.0001). Noninsulin-dependent diabetes mellitus was not an independent predictor of long-term cardiac death (hazard ratio: 1.09, P=0.41); however, insulin-dependent diabetes mellitus, chronic renal failure, peripheral vascular disease, and low ejection fraction were all independent risk factors for late cardiac death (all P<0.0001). The impact of comorbidities on the long-term risk of cardiac death was similar for the 3 groups. CONCLUSIONS: Noninsulin-dependent diabetes is not an independent predictor of late cardiac death after coronary artery bypass graft surgery, because cardiac-related survival is similar to that of nondiabetic patients for 6 years after surgery. In diabetic and nondiabetic patients, cardiac survival is adversely affected by the need for insulin therapy and/or the presence and number of comorbidities such as chronic renal failure, peripheral vascular disease, and low ejection fraction.

North American multicenter experience with the On-X prosthetic heart valve.

BACKGROUND AND AIM OF THE STUDY: This ongoing, longitudinal, multi-center, North American study was designed to evaluate the safety and effectiveness of the On-X valve. METHODS: The On-X valve was implanted in isolated aortic (AVR) and mitral (MVR) valve replacement patients at nine North American centers. Follow up was 98.6% complete. Anticoagulation compliance was evaluated by collection of international normalized ratio (INR) results in all patients throughout their postoperative follow up. Adverse events were recorded according to the AATS/STS guidance criteria. Hematologic studies were conducted postoperatively to evaluate hemodynamics and hemolysis. RESULTS: In total, 142 AVR and 142 MVR implants were performed; the mean follow up was 4.5 years; total follow up was 1,273 patient-years (pt-yr). At implant, the mean patient age was 59.2 years (range: 28 to 85 years); 71.8% of patients who underwent AVR and 33.1% who underwent MVR were males. Preoperatively, 89.4% of AVR patients and 56.3% of MVR patients were in sinus rhythm. The cardiac disease etiology was primarily stenotic, calcific degeneration in AVR and rheumatic or degenerative regurgitation in MVR. Hemolysis represented by postoperative elevation of serum lactate dehydrogenase was very low (median 217 IU after AVR and 251 IU after MVR at one year (82% AVR and 98% MVR of upper normal). Late adverse event rates were low, most notably thromboembolism (0.9%/pt-yr after AVR; 1.6%/pt-yr after MVR) and thrombosis. Kaplan-Meier event-free rates at five years were correspondingly high. Anticoagulation compliance analysis showed only about 40% of INR readings to be within target ranges postoperatively; thus, the control range achieved was much greater than the desired target, as might generally be expected for clinic-controlled INR. CONCLUSION: The On-X valve performed well in this study, confirming the original design intent of minimal hemolysis and low adverse event rates.

Influence of time elapsed between myocardial infarction and coronary artery bypass grafting surgery on operative mortality.

OBJECTIVE: Optimal timing for CABG surgery after myocardial infarction (MI) remains controversial. We examined the influence of patient age and time elapsed between MI and isolated CABG surgery on operative mortality. METHODS: Perioperative data of 13,545 patients who underwent isolated CABG surgery from 1991 to 2005 were reviewed. A previous MI was found in 7219 patients, classified among groups A-E whether they underwent surgery less than 6h (A, n=26), between 6 and 24h (B, n=51), between 1 and 7 days (C, n=313), between 8 and 30 days (D, n=917), or more than 30 days (E, n=5912) after the event. Crude percentages and odds ratio estimates of operative mortality were calculated. RESULTS: In patients who had no history of MI, the mortality rate was 1.7%, while it was, respectively, 19.2, 9.8, 8.6, 3.2, and 2.4% in patients from groups A to E. Among 6589 patients over 65 years of age, 3027 had no history of MI. Their mortality was 2.4%, compared to, respectively, 35.7, 13.8, 11.3, 5.1, and 3.9% for those belonging to groups A-E. Overall odds ratio estimates of operative mortality were 3.92 (p=0.19), 5.08 (p=0.002), 4.33 (p=0.0001), 1.50 (p=0.08), and 1.18 (p=0.24) for groups A-E, respectively. CONCLUSIONS: Operative mortality is not influenced by a history of MI sustained more than 30 days prior to isolated CABG surgery, but is highly and most significantly increased between 6h and 1 week after MI, especially in older patients. That critical period should be avoided whenever possible.

The mosaic valve clinical performance at seven years: results from a multicenter prospective clinical trial.

BACKGROUND AND AIM OF THE STUDY: The Mosaic valve is a third-generation stented porcine bioprosthesis built upon the historical durability of the Hancock II valve in an attempt to improve hemodynamic performance and durability. METHODS: This multicenter trial was prospective and non-randomized in design. Between February 1994 and October 1999, six centers following a common study protocol enrolled 797 patients (mean age 70 years: range: 21-88 years) who underwent aortic valve replacement (AVR), and 232 patients (mean age 68 years; range: 17-84 years) who underwent mitral valve replacement (MVR). The cumulative follow up was 3,442 patient-years (pt-yr) for AVR (mean 4.3 years; maximum 8 years), and 870 pt-yr for MVR (mean 3.7 years; maximum 7 years). Follow up was complete for 95% of AVR patients, and for 97% of MVR patients. RESULTS: The mean gradient and calculated effective orifice area average across all valve sizes remained stable at one, four and six years. Freedom from valve-related adverse events (mean +/- SE) at one, four and seven years after AVR were, respectively: Antithromboembolic-related hemorrhage (ARH) 97.0 +/- 0.6, 95.6 +/- 0.9, and 94.6 +/- 5.1%; primary hemolysis 100, 100, and 100%; and structural valve deterioration (SVD) 100, 100 and 100%. Freedom at one, four and seven years after MVR were: ARH 96.9 +/- 1.2, 95.6 +/- 2.0, and 95.6 +/- 7.6%; primary hemolysis 100, 100, and 100%; and SVD 100, 100, and 100%. CONCLUSION: These mid-term results demonstrate the clinical safety and excellent performance of the Mosaic valve. Continued follow up will determine if this new-design, third-generation bioprosthesis will provide increased durability.

Determinants of stroke after coronary artery bypass grafting.

OBJECTIVES: Cerebrovascular accidents (CVA) after CABG are deleterious complications whose prevention remains poorly defined. The aim of this study was to identify the determinants for CVA after CABG. METHODS: Nine thousand nine hundred and sixteen patients underwent CABG at our institution from January 1992 to June 2002. Data were prospectively collected and univariate/multivariate analyses conducted. RESULTS: Two hundred and eight patients (2.1%) suffered perioperative CVA. Univariate analysis showed a higher risk profile in the CVA group including advanced age, depressed percent left ventricular ejection fraction (LVEF), unstable angina, diabetes mellitus (DM), chronic renal failure (CRF), redo surgery, peripheral vascular disease (PVD), previous CVA, and higher Parsonnet score (P<0.001). Furthermore, the CVA group had longer myocardial ischemia (CVA 56.2 +/-40.9 vs. Control 50.4+/-20.9 min, P=0.03) and cardiopulmonary bypass (CPB) times (CVA 87.4+/-30.0 min vs. Control 78.9 +/-25.9 min, P<0.0001), and lower off-pump surgery rate (CVA 1.4% vs. Control 4.7%, P=0.01). Multivariable analysis identified seven preoperative and two perioperative determinants for CVA: LVEF<30% (odds ratio (OR)=2.49), previous CVA (OR=2.15), DM (OR=1.78), redo (OR=1.76), PVD (OR=1.66), CRF (OR=1.55), age (OR=1.03), perioperative intra-aortic balloon pump (OR=1.83), and transfusion rate (OR=1.59). Perioperative mortality was higher in the CVA group (CVA 18.6% vs. Control 2.6%, P<0.0001). CONCLUSIONS: Although occurrence of CVA seems mainly related to preoperative comorbidities, perioperative surgical variables, such as off-pump surgery, myocardial ischemia and cardiopulmonary bypass time, do not seem to independently influence CVA rate after CABG. In this regard CVA prevention should be performed before posing an indication to CABG, and closer evaluation of patients' risk profiles and tailored clinical/surgical strategies for those patients at higher risk for CVA occurrence should be included.