Long-term clinical outcomes of the Toronto stentless porcine valve: 15-year results from dual centers.

BACKGROUND AND AIM OF THE STUDY: The purpose of this study is to examine the long-term durability of the Toronto stentless porcine valve (SPV) in the aortic position (St Jude Medical, Minneapolis, MN). METHODS: We assessed the long-term clinical outcomes of 515 patients with aortic valve replacement (AVR) with the Toronto SPV from 1987 to 2001 at two centers, excluding early (<30 days) death. Median follow-up was 11.5 years (maximum 19.0 years). RESULTS: Average age was 64.2 ± 10.8 years, and females were 34% (173/515). The incidence of prosthesis-patient mismatch was low, 10.9%. Overall survival was 90.7 ± 1.3%, 75.4 ± 2.0%, and 56.8 ± 3.2% at 5, 10, and 15 years, respectively after surgery. Over the follow-up duration, 116 patients (23%) underwent repeated AVR: 90 for structural valve deterioration (SVD), 12 for endocarditis, 10 nonstructural valve dysfunction (10 aortic regurgitation due to aorta dilatation), and four for other reasons. The cumulative incidence of repeated AVR with death as a competing risk was 1.4% (95% confidence interval [CI], 0.6-2.7), 11.1% (95% CI, 8.4-14.2), and 34.4% (95% CI, 28.8-40.2) at 5, 10, and 15 years, respectively. Reoperative mortality was 5.2% (6/116). In SVD, the regurgitation type was dominant (82%). CONCLUSIONS: The Toronto SPV is associated with excellent survival and durability during the first decade of follow-up. However, regurgitation type of SVD increases from 10 years after operation with acceptable reoperative mortality. These findings may assist with prosthesis selection and reintervention strategy for failing stentless bioprosthesis.

Mending Hearts and Building Bridges: The Save a Child's Heart Foundation.

CONTEXT: Save a Child's Heart addresses the challenges of heart care for children in underdeveloped countries. OBJECTIVE: Save a Child's Heart has created a center of excellence for pediatric cardiac care at the Wolfson Medical Center in Israel, helped develop partner sites for evaluation and referral, and trained medical teams to return and build their own capacity for local cardiac care. RESULTS: Save a Child's Heart has treated more than 3600 children from 48 countries, with 50% from Iraq, Jordan, the Palestinian Authority, and Syria. In cooperation with the Palestinian Authority, Save a Child's Heart has examined more than 6000 children and treated 1750 children, trained 21 medical personnel, and conducted seminars for Palestinian medical personnel. The "Heart of the Matter Project," funded by the European Union, US Agency for International Development, the Palestinian Ministry of Health, and the Israeli Ministry of Regional Cooperation, is currently training a team at the Wolfson Medical Center from the Palestine Medical Complex in Ramallah and provides funds for Palestinian children's care in Israel. CONCLUSIONS: Save a Child's Heart is a model of a global humanitarian health care initiative with a single focus on heart disease in children. The "Heart of the Matter Project" is a model of health care based on regional cooperation despite local political tensions.

Determinants of pacemaker dependency after coronary and/or mitral or aortic valve surgery with long-term follow-up.

The aim of the present study was to investigate potential preoperative, operative, and postoperative predictors of pacemaker (PM) dependency after coronary, mitral valve, and aortic valve surgery. One hundred two patients (mean age 68 +/- 11 years; 62% men) who had received a permanent PM after cardiac surgery were included. The presence of any pacing activity in VVI mode with a lower rate of 30 beats/min was defined as PM dependency. Median time to PM implantation was 10 days after the index surgery. Pacemaker indications were atrioventricular block (AVB), sinus node dysfunction, and slow atrial fibrillation in 70%, 20%, and 11% of patients, respectively. At baseline, PM dependency rates were 0%, 9%, and 15% for patients with sinus node dysfunction, slow atrial fibrillation, and AVB, respectively (p = 0.158). Corresponding values at last follow-up were 15%, 9%, and 41% (p = 0.02). During long-term follow-up, new PM dependency developed in 21 patients (23%). Most patients had AVB as the PM indication (18 of 21 patients; 86%). Cumulative probabilities of freedom from PM dependency in patients with AVB were 63% and 30% at 5 and 10 years, respectively. Of several demographic, preoperative clinical, electrocardiographic, operative, and postoperative characteristics of patients, preoperative history of syncope (odds ratio [OR] 6.58, 95% confidence interval [CI] 1.11 to 38.87), body mass index >or=28.5 kg/m2 (OR 2.88, 95% CI 1.08 to 7.67), bypass time >or=105 minutes (OR 4.81, 95% CI 1.54 to 15.02), and AVB as PM indication (OR 5.14, 95% CI 1.51 to 17.44) were independent predictors of long-term PM dependency in multivariate logistic regression analysis. In conclusion, the long-term PM dependency rate was relatively high in patients with postoperative AVB requiring permanent PM implantation. A preoperative history of syncope, body mass index >or=28.5 kg/m2, bypass time of 105 minutes, and AVB as PM indication were independent predictors of long-term PM dependency after cardiac surgery.

The life and hard times of a coronary surgeon.

Coronary artery bypass is arguably the most extensively studied operation in surgical history. The technical advances and beneficial effects on symptoms and prognosis have been well documented over four decades. Percutaneous coronary interventions (PCIs) have also evolved through numerous modifications, and symptom relief has been substantiated; both modalities have been challenged by many randomized controlled trials. The rapid growth of PCIs has decreased coronary artery bypass volumes, and resulted in concerns about training, teaching, research, jobs and income. The most important concern, however, is the increasing 'off-label' application of PCIs with drug-eluting stents to a variety of untested coronary lesions. The randomized controlled trials studied a small fraction of those registered and excluded patients who are known to benefit from surgery and, thus, these studies were inherently biased. The results were then extrapolated to 'real-world' patients, who had been misinformed and misled about the performance and prognosis of coronary stents, as was later revealed in various registries. Hospitals should develop a collaborative revascularization strategy to provide patients and families with realistic alternatives.

Why is off-pump coronary surgery uncommon in Canada? Results of a population-based survey of Canadian heart surgeons.

BACKGROUND: Off-pump coronary artery bypass (OPCAB) is proposed to improve clinical outcomes and decrease resource use. However, off-pump surgery is not widely used in Canada. The purpose of this study was to determine the current use of OPCAB in Canada and determine why surgeons have not adopted this technique. METHODS AND RESULTS: The study was a population-based survey of all adult Canadian cardiac surgeons in practice >1 year. Eligible division heads and surgeons were contacted by mail. Of 19 806 isolated coronary bypass surgeries performed by respondents in Canada last year, 3164 (16.0%) were performed off-pump. More than 50% of Canadian surgeons performed OPCAB in <5% of coronary cases, and only 17% of surgeons performed OPCAB in >25% of coronary cases. Only 4 responding centers performed OPCAB in >25% of cases. Respondents were divided into those who performed <5% of cases off-pump (nonadopters), 5% to 25% off-pump (intermediate users), or >25% off-pump (enthusiasts). Mean number of distal anastomoses in off-pump cases were 1.7+/-0.6, 1.6+/-0.6, and 3.3+/-0.5 for nonadopters, intermediate users, and enthusiasts, respectively (P=0.001). Eleven percent of nonadopters, 55% of intermediate users, and 81% of enthusiasts believed OPCAB improved clinical outcomes (P<0.0001). Only 23% of all respondents felt OPCAB use would increase in the next 5 years. CONCLUSIONS: Concerns regarding incomplete revascularization and lack of proven clinical benefit have limited OPCAB to being performed routinely by only a small number of surgeons in Canada.

The short-term and long-term effects of warm or tepid cardioplegia.

BACKGROUND: Clinical studies of myocardial protection rarely identify differences in hard clinical outcomes after surgery, either early or late, because most trials lack sufficient statistical power to deal with low-frequency events. METHODS: Prospectively collected data concerning all isolated coronary bypass operations from November 1989 to February 2000 were analyzed to determine the effects of cold blood cardioplegia and warm or tepid blood cardioplegia on early and late outcomes after surgery. Warm blood cardioplegia was used in 4532 patients, whereas cold blood cardioplegia was used in 1532. The allocation of patients to receive warm blood cardioplegia and cold blood cardioplegia was random in 749 cases and according to surgeon preference in the remainder. Most patients in the cold blood cardioplegia group had surgery earlier in the time course of the study, and most in the warm blood cardioplegia group underwent surgery later. RESULTS: Perioperative death, myocardial infarction, and death or myocardial infarction were all more common in the cold blood cardioplegia group than in the warm blood cardioplegia group (death 2.5% vs 1.6%, P =.027, adjusted odds ratio 1.45, 95% confidence interval 0.95-2.22, P =.09; myocardial infarction 5.4% vs 2.4%, P <.0001, adjusted odds ratio 1.86, 95% confidence interval 1.36-2.53, P <.0001; death or myocardial infarction 7.3% vs. 3.8%, P <.0001, adjusted odds ratio 1.70, 95% confidence interval 1.30-2.21, P <.0001). Actuarial survival at 60 months was 91.1% +/- 1.4% in the warm blood cardioplegia group and 89.9% +/- 1.3% in the cold blood cardioplegia group (P =.09), whereas freedom from death or myocardial infarction was 84.7% +/- 1.8% and 83.2% +/- 1.6%, respectively (P =.16). In multivariate models, cold blood cardioplegia was associated with poorer survival (risk ratio 1.30, 95% confidence interval 0.96-1.75, P =.09) and freedom from any death or late myocardial infarction (risk ratio 1.93, 95% confidence interval 1.56-2.39, P =.0001). CONCLUSIONS: In 6064 patients undergoing isolated coronary artery bypass grafting, warm or tepid blood cardioplegia may be associated with better early and late event-free survivals than is cold cardioplegia.

Late outcomes in patients with uncorrected mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting.

OBJECTIVES: Patients undergoing coronary artery bypass grafting often have untreated mild to moderate mitral regurgitation. The long-term outcome of these patients follows an uncertain course. The purpose of this study was to examine the late outcomes in patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting. METHODS: One hundred sixty-three patients with mild to moderate mitral regurgitation at the time of isolated coronary artery bypass grafting were identified from the prospectively collected cardiovascular database at Sunnybrook and Women's College Health Sciences Centre. These patients were matched 1:2 with patients who had isolated coronary artery bypass grafting without mitral regurgitation according to gender, age, left ventricular ejection fraction, New York Heart Association functional class, vascular disease, diabetes, extent of coronary disease, and year of surgery. There was 99% complete follow-up. Actuarial survival and event-free (death, myocardial infarction, stroke, cardiac hospitalization, and cardiac reintervention) survivals were compared by log-rank methods. Cox regression was used to assess the effects of the presence of mitral regurgitation on late survival and event-free survival. Preliminary postoperative follow-up echocardiography was available for 49 of the 163 patients with mitral regurgitation. RESULTS: There were 489 patients in the matched-cohort study, 163 with mitral regurgitation and 326 without. The average length of follow-up was 3.37 +/- 2.04 years. There was no difference in actuarial survival at 6 postoperative years (mitral regurgitation 81.0% vs no mitral regurgitation 84.7%, P =.9185). Event-free survival at 6 years was worse in the mitral regurgitation group (45.7% vs no mitral regurgitation 64.7%, P =.0258). Patients with mitral regurgitation had worse functional status (New York Heart Association class 3-4 20.0%, n = 30/150, vs no mitral regurgitation 8.1%, n = 25/307, P =.0046). After the matched variables were controlled for, the hazard ratios associated with the presence of mitral regurgitation by Cox regression were 0.958 (P =.7626) for survival and 1.198 (P =.0333) for event-free survival. The only other significant predictor of late survival was preoperative intra-aortic balloon pump insertion (hazard ratio 2.484, P =.0365). Of the patients who underwent follow-up echocardiography, 30.6% (n = 15/49) had progression of mitral regurgitation to moderate to severe degree at an average of 16.4 postoperative months. CONCLUSION: Overall late survival was not affected by the presence of mild to moderate degrees of mitral regurgitation in patients undergoing coronary artery bypass grafting. However, these patients had poorer event-free survival and worse late functional status. In a subset of patients with echocardiographic follow-up, the postoperative course of mitral regurgitation was variable, and nearly a third of these patients had worsening mitral regurgitation. Consideration should be given to repairing moderate mitral regurgitation in selected cases to improve long-term quality of life.

Radial artery use is safe in patients with moderate to severe left ventricular dysfunction.

BACKGROUND: Using radial artery grafts in patients with moderate to severe left ventricular dysfunction (LVD; ejection fraction < 35%) has been discouraged for the fear that postoperative vasopressor support may cause graft spasm and lead to ischemic complications. We, therefore, examined the safety of radial grafts in aortocoronary bypass (ACB) patients with LVD. METHODS: Data were collected from 5,455 patients who underwent isolated ACB between January 1995 and September 2001. One thousand eight hundred three patients received a radial artery graft (RadACB), and 3,652 patients did not (NoRadACB). Three hundred seven RadACB, and 819 NoRadACB operations were performed in LVD patients. A matched (age, sex, urgency of operation, diabetes, and renal insufficiency) cohort analysis was performed in LVD patients. Univariate and logistic regression analyses were performed in the entire population and the unmatched RadACB and NoRadACB patient subgroups to examine the effect of radial artery use on postoperative death or myocardial infarction rate. RESULTS: The matched cohort analysis revealed a similar rate of death or myocardial infarction (RadACB, 11 of 242 patients; NoRadACB, 16 of 242 patients; p = 0.32). Left ventricular dysfunction was associated with a higher rate of death or myocardial infarction in both unmatched groups (RadACB, odds ratio, 2.36; 95% confidence interval, 1.38 to 4.58; p = 0.004; NoRadACB, odds ratio, 1.62; 95% confidence interval, 1.18 to 2.24; p < 0.001) and in the entire population (odds ratio, 1.77; 95% confidence interval, 1.32 to 2.35; p = 0.003). An interaction term for patients with LVD and a radial artery graft, which was forced into the logistic regression model for the entire population, was not predictive of death or myocardial infarction (odds ratio, 1.52; 95% confidence interval, 0.75 to 3.10; p = 0.25). CONCLUSIONS: Left ventricular dysfunction carries similar risk for postoperative death or myocardial infarction in RadACB and NoRadACB patients. The presence of LVD in isolation is not a contraindication to the use of radial grafting.

Patient prosthesis mismatch is rare after aortic valve replacement: valve size may be irrelevant.

BACKGROUND: Although small valve size and patient-prosthesis mismatch are both considered to decrease long-term survival, little direct evidence exists to support this hypothesis. METHODS: To assess the prevalence of patient-prosthesis mismatch and the influence of small valve size on survival, we prospectively studied 1,129 consecutive patients undergoing aortic valve replacement between 1990 and 2000. Mean and peak gradients and indexed effective orifice area were measured by transthoracic echocardiography postoperatively (3 months to 10 years). Abnormal postoperative gradients were defined as those patients with mean or peak gradient above the 90th percentile (mean gradient > or = 21 or peak gradient > or = 38 mm Hg). Patient-prosthesis mismatch was defined as those patients with indexed effective orifice area below the 10th percentile (< 0.60 cm2/m2). RESULTS: A multivariable analysis identified internal diameter of the implanted valve as the only independent predictor of abnormal gradients postoperatively. However, there was no significant difference in actuarial survival between normal and abnormal gradient groups (7 years: 91.2% +/- 1.5% versus 95.0% +/- 2.2%; p = 0.48). Freedom from New York Heart Association class III or IV (7 years: 74.5% +/- 3.1% versus 74.6% +/- 6.2%; p = 0.66) and left ventricular mass index were not different between normal and abnormal gradient groups. Patients with and without patient-prosthesis mismatch were similar with respect to postoperative left ventricular mass index, 7-year survival (95.1% +/- 1.3% versus 94.7% +/- 3.0%; p = 0.54), and 7-year freedom from New York Heart Association class III or IV (79.3% +/- 6.6% versus 74.5% +/- 2.5%; p = 0.40). In patients with patient-prosthesis mismatch and abnormal gradients, the majority had prosthesis dysfunction owing to degeneration. CONCLUSIONS: Severe patient-prosthesis mismatch is rare after aortic valve replacement. Patient-prosthesis mismatch, abnormal gradient, and the size of valve implanted do not influence left ventricular mass index or intermediate-term survival.

Are stentless valves hemodynamically superior to stented valves? A prospective randomized trial.

BACKGROUND: Although stentless aortic bioprostheses are believed to offer improved outcomes, hemodynamic benefits remain unsubstantiated. METHODS: Fifty-three patients were randomized to receive the stented C-E pericardial valve (CE) and 46 patients the Toronto Stentless Porcine valve (SPV). Annuli were sized for the optimal insertion of both valve types, such that surgeons were required to commit to specific valve sizes before randomization. Echocardiographic measurements and functional status (Duke Activity Status Index) were assessed at 3 and 12 months postoperatively. RESULTS: Although cardiopulmonary bypass times (CE: 118.6+/-36.3 minutes; SPV: 148.5+/-30.9 minutes; p = 0.0001) and aortic cross-clamp times (CE: 95.4+/-28.6 minutes; SPV: 123.6+/-24.1 minutes; p = 0.0001) were significantly prolonged in the SPV group, perioperative morbidity and mortality was similar between groups. Neither valve offered a superior internal diameter for any given annular diameter (mean decrease in left ventricular outflow tract diameter after valvular implantation: SPV: 3.4+/-1.11 mm versus CE: 3.7+/-1.33 mm; p = 0.25). Although labeled mean valve size was significantly larger in the SPV group, the actual mean valve size based on internal valvular diameter was no different between groups (CE: 21.9+/-2.0 mm; SPV: 22.3+/-2.0 mm; p = 0.286). Although effective orifice areas increased, and mean and peak transvalvular gradients decreased in both groups over time, no differences were demonstrated between groups at 12 months. Similarly, although significant regression of left ventricular mass was accomplished in both groups over time, no differences were demonstrated between groups. Finally, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups at 12 months postoperatively. CONCLUSIONS: Although offering excellent outcomes, stentless valves did not demonstrate superior hemodynamic indices in comparison to stented valves up to 12 months after implantation.

Impact of small valve size on hemodynamics and left ventricular mass regression with the Toronto SPV stentless aortic bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: The hemodynamic performance of stentless aortic bioprostheses has been previously well described. Because the potential for prosthesis-patient mismatch is greatest for small valves in the aortic position, the present study sought to compare the hemodynamic performance and degree of left ventricular (LV) mass regression between valve sizes for the Toronto SPV valve, with special interest in measures of relief of LV outflow obstruction afforded by the smallest valves. METHODS: This study included 257 patients (178 men, 79 women; mean age 63.5+/-11.4 years; range: 34-93 years) from six investigative centers with complete echocardiography/Doppler data obtained through three years. Valve sizes implanted were 21 mm (n = 11), 23 mm (n = 23), 25 mm (n = 58), 27 mm (n = 83), and 29 mm (n = 82). Echocardiography was performed at discharge, six months, one year, and yearly thereafter, and interpreted in a centralized core laboratory. Mean gradient, effective orifice area (EOA), indexed EOA, and absolute and percent change in LV mass index were used as markers of hemodynamic performance. RESULTS: For all valve sizes, mean and peak gradients fell and EOA increased early after surgery. There were no differences between groups in the degree to which gradients fell, and EOA increased from discharge to one year follow up. At one year, indexed EOA was 0.9 cm2/m2 for valve sizes 21 and 23 mm, and 1.0-1.2 cm2/m2 for sizes 25, 27 and 29 mm. There was statistically significant LV mass regression for all valve sizes (p <0.05), and no differences between valve sizes in the magnitude of absolute or percent change in LV mass index between baseline and three years. CONCLUSION: The Toronto SPV valve demonstrates excellent parameters of hemodynamic performance for all valve sizes, including the smallest valves used in only a minority of patients. Findings of indexed EOA > or = 0.9 cm2/m2, and equivalent degrees of LV mass regression for all valve sizes, reinforces the excellent hemodynamic performance of stentless aortic bioprostheses, and suggests that prosthesis-patient mismatch should be minimized with these valves.

Durability and prevalence of aortic regurgitation nine years after aortic valve replacement with the Toronto SPV stentless bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: Stentless aortic bioprostheses have excellent hemodynamics. Previous investigations of the Toronto SPV valve described a correlation between the occurrence of significant aortic regurgitation (AR) and dilation of the sinotubular junction. The study aim was to determine the long-term durability and determinants of AR at nine years in a large, multicenter study of the Toronto SPV valve. METHODS: The study included 447 patients from six centers. Clinical outcomes and echocardiographic data (gradients, effective orifice area index (EOA-I), left ventricular mass, aortic root dimensions, and presence and severity of AR) were collected prospectively. A multivariable logistic regression model was used to evaluate clinical and echocardiographic variables for impact on the occurrence of AR. RESULTS: Total follow up was 2,660 patient-years (mean 6.0 +/- 2.5 years; range: 0 to 11.1 years). Mean gradient and EOA-I remained unchanged through nine years. There were 17 cases of structural deterioration, of which 15 underwent explantation. The mechanism of failure was predominantly leaflet tear in the setting of sinotubular dilation. Freedom from explant for structural failure was 90.1% at nine years (100% for patients aged > or = 65 years). Freedom from hemodynamically significant AR was 96.9% at five years and 82.5% at nine years. Determinants of AR were longer duration of follow up, larger valve size, and increase in the ratio of sinotubular junction to the size of valve implanted. CONCLUSION: At nine years after implantation of the Toronto SPV valve, hemodynamics remained excellent. There was good freedom from structural deterioration through nine years, and structural failure occurred due to aortic root dilation and leaflet tear, without significant valve calcification. AR tends to occur with longer follow up, larger valve sizes, and dilation of the sinotubular junction.

The influence of cardiopulmonary bypass flow characteristics on the clinical outcome of 1820 coronary bypass patients.

OBJECTIVE: To determine whether pulsatile perfusion is clinically beneficial for adult cardiac operations. METHODS: Data concerning consecutive patients undergoing isolated coronary bypass surgery (n=1820) from January 1, 1997 to July 31, 1999 were reviewed. RESULTS: Nine hundred fifteen patients received pulsatile perfusion (PP) while perfusion in the remaining 905 patients was nonpulsatile (NP). Patients in the PP group were older (64.0 +/- 9.2 years versus 63.1 +/- 9.9 years) and experienced more of the following: urgent operations (42.4% versus 38.0%), preoperative intra-aortic balloon pump (4.8% versus 1.8%), preoperative cerebrovascular accidents (CVA; 3.1% versus 1.3%) and renal insufficiency (10.5% versus 7.0%). The PP group had higher incidence of early postoperative mortality (2.6% versus 1.5%), CVA (3.1% versus 1.3%), need for dialysis (3.2% versus 2.2%) and longer hospital stay (9.2 +/- 8.3 days versus 8.5 +/- 5.8 days). The incidence of postoperative myocardial infarction and renal dysfunction was similar in both groups (2.0% versus 2.2% and 3.3% versus 3.9% respectively; not significant). Because of the significant difference in preoperative parameters for the PP and NP groups, the following three statistical techniques were used to isolate the effect of perfusion characteristics on operative outcome: multiple regression, propensity score and risk stratification. Multivariate analysis did not find PP to be protective against mortality, morbidity and mortality, and CVA or for the development of postoperative renal dysfunction. When propensity score analysis was applied, the incidence of cardiac morbidity and mortality was strongly associated with the quintile (first quintile 6.7%, fifth quintile 27.0%, P<0.001). Multivariate analysis including quintiles did not find PP to be an independent predictor for mortality or for morbidity and mortality. Risk stratification was performed for age and for preoperative creatinine clearance levels. In all groups, PP did not seem to reduce the incidence of morbidity, morbidity and mortality, or the development of postoperative renal dysfunction. In patients with preoperative renal dysfunction, mean postoperative creatinine levels and the need for dialysis following surgery were similar in the PP and NP groups. CONCLUSION: Pulsatile flow does not appear to offer any clinical benefit over nonpulsatile flow for cardiac surgery patients.

Impact of preoperative renal dysfunction on cardiac surgery results.

Results of cardiac surgery were analyzed using a database that included plasma creatinine levels in 2,214 patients, of whom 507 had preoperative renal dysfunction (creatinine clearance < 0.9 mL x s(-1) x m(-2)). Logistic regression and propensity score analyses found preoperative renal dysfunction to be an independent predictor of morbidity and mortality. Plotting preoperative creatinine clearance against morbidity and mortality revealed an exponential increase in morbidity and mortality when preoperative creatinine clearance was < 0.84 mL x s(-1) x m(-2). Patients were stratified for age, operative procedure, and comorbidity. In all stratified groups, preoperative creatinine clearance < 0.84 mL x s(-1) x m(-2) was associated with similar exponential increases in morbidity and mortality. In patients with preoperative renal dysfunction, elevated plasma creatinine levels persevered for 6 months postoperatively. Dialysis beyond postoperative day 10 was required in < 2% of patients with preoperative plasma creatinine of 160-200 micro mol x L(-1) and in 5% in those with creatinine > 200 micro mol x L(-1) (p < 0.05). Actuarial survival was significantly reduced (< 90% at 18 months postoperatively) in patients with preoperative renal dysfunction.

Impact of clopidogrel use on mortality and major bleeding in patients undergoing coronary artery bypass surgery.

Patients who received clopidogrel prior to coronary bypass surgery are at increased risk for bleeding that must be balanced with risk of ongoing ischemia if coronary artery bypass grafting is delayed. This study aimed to evaluate the impact of clopidogrel on mortality and major bleeding in patients undergoing urgent coronary bypass surgery. We reviewed 451 consecutive patients who underwent urgent isolated coronary bypass surgery; 262 had not received clopidogrel, whereas 189 received clopidogrel < or = 5 days preoperative. The primary endpoint was in-hospital death, massive transfusion or massive blood loss. Patient characteristics were almost similar between groups. There was no difference in in-hospital death or massive bleeding indices between groups (clopidogrel: 7% vs. no clopidogrel: 6%, P = 0.9). No difference was observed even after adjusting for the date of stopping clopidogrel preoperatively. Multivariate regression analysis showed that clopidogrel or the duration it was stopped preoperatively, did not predict adverse outcomes. Significant independent predictors included preoperative renal dysfunction, hemoglobin level and peripheral vascular disease. clopidogrel, or the time it was stopped prior to surgery, was not a risk factor for in-hospital death, massive bleeding, or other poor early outcomes in patients undergoing urgent coronary artery bypass surgery.

Are stentless valves hemodynamically superior to stented valves? Long-term follow-up of a randomized trial comparing Carpentier-Edwards pericardial valve with the Toronto Stentless Porcine Valve.

OBJECTIVE: The benefit of stentless valves remains in question. In 1999, a randomized trial comparing stentless and stented valves was unable to demonstrate any hemodynamic or clinical benefits at 1 year after implantation. This study reviews long-term outcomes of patients randomized in the aforementioned trial. METHODS: Between 1996 and 1999, 99 patients undergoing aortic valve replacement were randomized to receive either a stented Carpentier-Edwards pericardial valve (CE) (Edwards Lifesciences, Irvine, Calif) or a Toronto Stentless Porcine Valve (SPV) (St Jude Medical, Minneapolis, Minn). Among these, 38 patients were available for late echocardiographic follow-up (CE, n = 17; SPV, n = 21). Echocardiographic analysis was undertaken both at rest and with dobutamine stress, and functional status (Duke Activity Status Index) was compared at a mean of 9.3 years postoperatively (range, 7.5-11.1 years). Clinical follow-up was 82% complete at a mean of 10.3 years postoperatively (range, 7.5-12.2 years). RESULTS: Preoperative characteristics were similar between groups. Effective orifice areas increased in both groups over time. Although there were no differences in effective orifice areas at 1 year, at 9 years, effective orifice areas were significantly greater in the SPV group (CE, 1.49 +/- 0.59 cm(2); SPV, 2.00 +/- 0.53 cm(2); P = .011). Similarly, mean and peak gradients decreased in both groups over time; however, at 9 years, gradients were lower in the SPV group (mean: CE, 10.8 +/- 3.8 mm Hg; SPV, 7.8 +/- 4.8 mm Hg; P = .011; peak: CE, 20.4 +/- 6.5 mm Hg; SPV, 14.6 +/- 7.1 mm Hg; P = .022). Such differences were magnified with dobutamine stress (mean: CE, 22.7 +/- 6.1 mm Hg; SPV, 15.3 +/- 8.4 mm Hg; P = .008; peak: CE, 48.1 +/- 11.8 mm Hg; SPV, 30.8 +/- 17.7 mm Hg; P = .001). Ventricular mass regression occurred in both groups; however, no differences were demonstrated between groups either on echocardiographic, magnetic resonance imaging, or biochemical (plasma B-type [brain] natriuretic peptide) assessment (P = .74). Similarly, Duke Activity Status Index scores of functional status improved in both groups over time; however, no differences were noted between groups (CE, 27.5 +/- 19.1; SPV, 19.9 +/- 12.0; P = .69). Freedom from reoperation at 12 years was 92% +/- 5% in patients with CEs and 75% +/- 5% in patients with SPVs (P = .65). Freedom from valve-related morbidity at 12 years was 82% +/- 7% in patients with CEs and 55% +/- 7% in patients with SPVs (P = .05). Finally, 12-year actuarial survival was 35% +/- 7% in patients with CEs and 52% +/- 7% in patients with SPVs (P = .37). CONCLUSION: Although offering improved hemodynamic outcomes, the SPV did not afford superior mass regression or improved clinical outcomes up to 12 years after implantation.

Troponin after cardiac surgery: a predictor or a phenomenon?

BACKGROUND: Increased cardiac troponin is observed after virtually every cardiac operation, indicating perioperative myocardial injury. The clinical significance of this elevation is controversial. This study aimed to correlate postoperative troponin levels with major adverse cardiac events (MACE). METHODS: The study included 1918 consecutive patients undergoing adult cardiac operations, including 1515 isolated coronary procedures, 229 valvular operations, and 174 combined coronary/valve procedures. Peak troponin T (normal value < 0.1 microg/L) was measured at less than 24 hours postoperatively. Excluded were 506 patients with a recent myocardial infarction (< 30-days of operation). The primary outcome was a composite of death, electrocardiogram-defined infarction, and low output syndrome (MACE). RESULTS: Mortality rates were 1.4%, 6.1%, and 7% in the coronary bypass, valve, and combined groups, respectively (p < 0.001). The rates of MACE were 17%, 35%, and 44% (p < 0.0001), and mean troponin T levels were 0.9 +/- 1.5, 1.2 +/- 2.9, and 1.3 +/- 1.2 microg/L (p < 0.001), in the coronary bypass, valve, and combined groups, respectively. All patients were divided into quintiles based on their peak postoperative troponin level (Q1, 0.0 to 0.39; Q2, 0.4 to 0.59; Q3, 0.6 to 0.79; Q4, 0.8 to 1.29; and Q5, > 1.3 microg/L). Adverse outcomes were similar and stable in the lower quintiles. A stepwise increase in adverse outcomes was observed in the higher quintiles. Receiver operating characteristic curve analysis revealed a troponin cutoff of 0.8 microg/L was the most discriminatory for MACE (area under the curve, 0.7). Multivariable analyses showed a troponin value of more than 0.8 microg/L was independently associated with MACE. CONCLUSIONS: Moderate elevations in troponin are common after cardiac operations; troponin is a well-described predictor of outcomes. Troponin levels exceeding 0.8 microg/L are associated with increased MACE in patients without a history of preoperative myocardial infarction within 30 days of operation.

History of surgical treatment of ischemic heart disease--pre-'coronary bypass grafting' era.

BACKGROUND AND AIM: To review the various concepts, surgical experiments, and actual procedures performed for the treatment of ischemic heart disease, which eventually led to the evolution of direct coronary artery bypass surgery. METHODS: References were collected from original articles and through pubmed search. RESULTS: Various concepts and procedures were introduced, all with the aim of increasing myocardial blood flow and relief of angina. These included creation of vascular adhesions, denervation, thyroidectomies, using other organs for providing blood supply, and intramyocardial implantation of bleeding systemic arteries. CONCLUSION: Historically various innovative concepts existed and a variety of procedures were performed for treating ischemic myocardium, with variable results. These procedures continued till the evolution of direct coronary artery bypass grafting.