Vei Vei Lee

Early and Late Mortality of Patients Undergoing Aortic Valve Replacement After Previous Coronary Artery Bypass Graft Surgery

BACKGROUNDnIn a small number of patients who undergo coronary artery bypass graft surgery (CABG), a hemodynamically significant aortic valve lesion requiring aortic valve replacement (AVR) develops as they grow older. In a limited number of studies in small patient groups, high mortality has been shown in patients undergoing AVR after CABG. We undertook this study to determine the mortality risk factors for patients who undergo AVR after CABG procedures.nnnMETHODS AND RESULTSnThe outcome of 104 patients treated at our institution between January 1983 and December 1993 was retrospectively reviewed. The initial surgery was CABG in all patients. The patient population included 86 men (83%) and 18 women (17%); their mean age was 67 years. Overall, 70% of patients had congestive heart failure, and 96% had multivessel coronary artery disease. The diagnosis was aortic stenosis in 68% of patients, aortic insufficiency in 16%, and combined aortic stenosis and aortic insufficiency in 16%. Postoperative complications included worsening congestive heart failure (35%), perioperative myocardial infarction (13%), and bleeding (28%). The early mortality was 14%, and the late mortality was 17% (mean follow-up, 35 months). The risk factors for early mortality were number of diseased vessels (P = .028), renal failure (0.000), and prior myocardial infarction (P = .028). A perioperative predictor of early mortality was cardiopulmonary bypass time (P = .000). The risk factors for late mortality included preoperative diabetes mellitus (P = .007), postoperative acute respiratory distress syndrome (P = .011), and ventricular arrhythmias (P = .0001). The survival at 1, 5, and 10 years was 96%, 75%, and 49%, respectively.nnnCONCLUSIONSnRisk factors were identified for early and late mortality in patients undergoing AVR after previous CABG. Although early morbidity and mortality were high, the longterm outcome of the survivors was favorable.

Short- and long-term outcomes of coronary artery bypass grafting or drug-eluting stent implantation for multivessel coronary artery disease in patients with chronic kidney disease.

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD), but no study has yet compared the short- and long-term outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) with drug-eluting stents for multivessel CAD among non-hemodialysis-dependent (HD) patients with CKD. In our institutions registry, we identified 812 patients with CKD (glomerular filtration rate <60 ml/min) who had undergone either CABG or PCI for multivessel CAD from May 2003 to December 2006. Of these patients, 725 had non-HD CKD, and 87 were hemodialysis-dependent. The rates of 30-day and long-term mortality, 30-day major adverse cardiovascular events, and hemodialysis dependence after revascularization were compared between these 2 groups by computing the hazard ratios from a Cox proportional hazards model and adjusting them for the baseline covariates and propensity score. After either CABG or PCI, 2.4% of the patients with non-HD CKD were hemodialysis dependent. Compared to PCI, CABG was associated with postoperative hemodialysis dependence (odds ratio 3.2, 95% confidence interval 1.1 to 9.3; p <0.001). However, among patients with non-HD CKD and 3-vessel CAD, those who underwent CABG tended to have a lower long-term mortality rate than those who underwent PCI (hazard ratio 0.61, 95% confidence interval 0.36 to 1.03; p = 0.06). In the patients with non-HD CKD treated for 2-vessel CAD, those who underwent CABG or PCI had a similar long-term mortality risk (hazard ratio 1.12, 95% confidence interval 0.52 to 2.34; p = 0.7). In conclusion, in patients with non-HD CKD and multivessel CAD, CABG led to better survival than PCI with drug-eluting stents, but CABG patients had a greater short-term risk of requiring permanent hemodialysis.

Prosthesis–patient mismatch affects long-term survival after mechanical valve replacement

OBJECTIVEnWe sought to examine the relationship between the degree of prosthesis-patient mismatch and long-term survival after mechanical aortic valve replacement.nnnMETHODSnProspectively collected long-term follow-up data from 469 consecutive patients who underwent aortic valve replacement between 1995 and 1998 were reviewed. The indexed effective orifice area was derived from the reference normal values of effective orifice area divided by the patients body surface area. Outcome was stratified according to the severity of prosthesis-patient mismatch: moderate mismatch was defined as 0.65 to 0.85 cm(2)/m(2) and severe mismatch as less than 0.65 cm(2)/m(2). The Cox proportional-hazards model with propensity score adjustment was used to adjust for the observed differences in baseline characteristics between the mismatch groups.nnnRESULTSnThe degree of prosthesis-patient mismatch was minimal in 57% of patients, moderate in 39%, and severe in 4%. Predictors of clinically significant mismatch included small aortic valve sizes (19 and 21 mm), obesity, age greater than 65 years, and class III or IV heart failure. During a median follow-up period of approximately 7.9 years, overall survival was 77% in patients with minimal mismatch, 63% in those with moderate mismatch, and only 47% in those with severe mismatch (P < .001). Moderate or severe mismatch was a significant predictor of poorer survival (hazard ratio, 1.6; 95% confidence interval, 1.4-2.3; P < .01), even after adjustment for all significant clinical predictors (ie, propensity score; hazard ratio, 1.2; 95% confidence interval, 1.0-1.5; P = .05).nnnCONCLUSIONSnIn a large aortic valve surgery population, prosthesis-patient mismatch occurred in 43% of patients, and those with significant mismatch had worse long-term outcomes than those with minimal mismatch.

Moderate hypothermia during aortic arch surgery is associated with reduced risk of early mortality

OBJECTIVEnSelective antegrade cerebral perfusion (ACP) during hypothermic circulatory arrest (HCA) provides cerebral protection during aortic arch surgery. However, the ideal temperature for HCA during ACP remains unknown. Clinical outcomes were compared in patients who underwent moderate (nasopharyngeal temperature, ≥ 20 °C) versus deep (nasopharyngeal temperature, <20 °C) HCA with ACP during aortic arch repair.nnnMETHODSnBy using a prospectively maintained clinical database, we analyzed data from 221 consecutive patients who underwent aortic arch replacement with HCA and ACP between December 2006 and May 2009. Seventy-eight patients underwent deep hypothermia (mean lowest temperature, 16.8 °C ± 1.7 °C) and 143 patients underwent moderate hypothermia (mean, 22.9 °C ± 1.4 °C) before systemic circulatory arrest was initiated. Multivariate stepwise logistic and linear regressions were performed to determine whether depth of hypothermia independently predicted postoperative outcomes and blood-product use.nnnRESULTSnCompared with moderate hypothermia, deep hypothermia was associated independently with a greater risk of in-hospital death (7.7% vs 0.7%; odds ratio [OR], 9.3; 95% confidence interval [CI], 1.1-81.6; P = .005) and 30-day all-cause mortality (9.0% vs 2.1%; OR, 4.7; 95% CI, 1.2-18.6; P = .02), and with longer cardiopulmonary bypass time (154 ± 62 vs 140 ± 46 min; P = .008). Deep hypothermia also was associated with a higher incidence of stroke, although this association was not statistically significant (7.6% vs 2.8%; P = .073; OR, 4.3; 95% CI, 0.9-12.5). No difference was seen in acute kidney injury, blood product transfusion, or need for surgical re-exploration.nnnCONCLUSIONSnModerate hypothermia with ACP is associated with lower in-hospital and 30-day mortality, shorter cardiopulmonary bypass time, and fewer neurologic sequelae than deep hypothermia in patients who undergo aortic arch surgery with ACP.

Preoperative Statin Therapy Decreases Risk of Postoperative Renal Insufficiency

INTRODUCTIONnAlthough current guidelines recommend withholding statins in perioperative patients, little information is available on whether perioperative statin use increases risk for postoperative renal failure.nnnAIMSnWe examined the relation between preoperative statin therapy and postoperative risk for renal insufficiency in patients undergoing cardiac surgery.nnnMETHODSnRetrospective cohort review from the Texas Heart Institute research database was performed. Patients were divided into two groups: those who received preoperative statins and those who did not. Primary outcome was the development of postoperative renal insufficiency (requiring dialysis or not). Outcomes were assessed in the entire cohort and in subgroups undergoing isolated coronary artery bypass grafting (CABG), isolated valve surgery, or combined CABG and valve surgery.nnnRESULTSnOf 3001 patients, 56% received preoperative statins. In multivariate logistic regression analysis, preoperative statins were associated with significant reductions in risk for postoperative renal insufficiency in the entire cohort (odds ratio [OR]= 0.60, 95% confidence interval [CI] 0.38-0.95) and in patients undergoing isolated CABG (OR = 0.34, 95% CI 0.17-0.68). In patients undergoing isolated valve surgery (OR = 1.35, 95% CI 0.61-2.96) or combined CABG and valve surgery (OR = 1.39, 95% CI 0.48-3.99), preoperative statins were not associated with decreased incidence of postoperative renal insufficiency. Age >65 years, preoperative renal insufficiency, history of congestive heart failure, preoperative intra-aortic balloon pump insertion, and total cardiopulmonary bypass time >80 min were also independent predictors associated with increased risk for postoperative renal insufficiency.nnnCONCLUSIONSnPreoperative statin therapy was associated with decreased incidence of postoperative renal insufficiency in patients undergoing cardiac surgeries, particularly in patients undergoing isolated CABG.

Difference in Patient Profiles and Outcomes in Japanese Versus American Patients Undergoing Coronary Revascularization (Collaborative Study by CREDO-Kyoto and the Texas Heart Institute Research Database)

Although coronary revascularization is common in both Japan and the United States (US), no direct comparison has been performed to demonstrate differences in the clinical characteristics and long-term outcomes of patients in these 2 countries. We analyzed the preprocedural, in-hospital, and long-term data from the Coronary Revascularization Demonstrating Outcome registry (Kyoto, Japan) and the Texas Heart Institute Research Database (Houston, Texas) of 16,100 patients who had undergone elective, initial percutaneous coronary intervention or coronary artery bypass grafting. The Japanese procedures were performed from 2000 to 2002 (n = 8,871, follow-up period 3.5 years, interquartile range 2.6 to 4.3) and the US procedures from 1999 to 2003 (n = 7,229, follow-up period 5.2 years, interquartile range 3.8 to 6.5). The Japanese patients tended to be older (mean age 67.2 vs 62.7 years; p <0.001), to smoke (52.9% vs 46.0%; p <0.001), and to have diabetes (39.2% vs 31.0%; p <0.001) and stroke (16.4% vs 5.0%; p <0.001). The US patients were more obese (body mass index 23.7 vs 29.3 kg/m(2); p <0.001), with greater rates of systemic atherosclerotic disease. Both groups had a similar in-hospital mortality rate (Japanese patients 0.9% vs US patients 1.1%; p = 0.19) and crude long-term mortality rate (Japanese patients 27.7/1,000 person-years, US patients 28.2/1,000 person-years; p = 0.35). After adjustment for known predictors, the US group had greater long-term mortality than the Japanese group (hazard ratio 1.71, 95% confidence interval 1.50 to 1.95; p <0.001). This finding was consistent among all high-risk subgroups. In conclusion, the 2 registries showed similar crude outcomes but important differences in patient risk factors such as obesity. In the adjusted analysis, the Japanese patients had better outcomes than did the US patients. Additional study is needed to assess the effect of ethnic and risk factor variations on coronary artery disease.

Association of gender with morbidity and mortality after isolated coronary artery bypass grafting. A propensity score matched analysis

INTRODUCTIONnThere is conflicting evidence about the impact of gender on outcomes after coronary artery bypass grafting (CABG).nnnMETHODSnWe performed a multivariate logistic regression and propensity score matched analyses in 13,115 patients (75% men) who underwent CABG between January 1, 1995 and December 31, 2009. The primary outcome was in-hospital mortality. Secondary outcomes included post-operative respiratory failure, stroke, myocardial infarction, sternal and leg wound infections, atrial fibrillation (AF), renal failure, need for postoperative intra-aortic balloon pump (IABP) support, and length of hospital stay.nnnRESULTSnA higher proportion of women (184; 5.6%) suffered in-hospital death compared to men (264; 2.7%), p<0.0001. After propensity score matching (n=3600 total, 1800 in each group), female gender was an independent predictor of mortality after isolated CABG (odds ratio [OR]=1.84; 95% confidence interval [CI] 1.22-2.78). Women also experienced a higher incidence of postoperative complications including stroke (3.8% vs. 2.3%, OR 1.37; 95% CI 1.08-1.73) and leg wound infection (3.4% vs. 1.7%, OR 1.75; 95% CI 1.36-2.54) on multivariate regression analyses. However, these differences were not significant after propensity score matching. We also observed a lower risk of post-operative AF (21.2% vs. 22.1%, OR 0.78; 95% CI 0.70-0.86) in women that remained significant after propensity matching (O.R. 0.76; 95% C.I. 0.65-0.90). Length of hospital stay was longer in women compared with men (11.9 ± 9.0 vs. 10.4 ± 9.2 days, p<0.0001).nnnCONCLUSIONSnFemale gender is an independent predictor of increased mortality and a lower incidence of post-operative AF after isolated CABG.

Usefulness of Single Nucleotide Polymorphism in Chromosome 4q25 to Predict In-Hospital and Long-Term Development of Atrial Fibrillation and Survival in Patients Undergoing Coronary Artery Bypass Grafting

We aimed to determine whether polymorphisms in chromosome 4q25 are associated with postoperative atrial fibrillation (AF), long-term AF, postoperative or long-term stroke, and long-term survival after coronary artery bypass grafting. We performed genotyping for rs2200733 and rs10033464 in white participants (n = 1,166) from the TexGen genetic registry. The development of postoperative or long-term AF, postoperative or long-term stroke, and long-term mortality were ascertained. Both rs2200733 and rs10033464 were associated with postoperative AF (odds ratio [OR] 1.41, 95% confidence interval [CI] 1.04 to 1.91, and OR 1.47, 95% CI 1.05 to 2.06, respectively). Carriers of the risk allele (T) had an increased risk of postoperative AF with preoperative β blocker (BB) (for rs2200733, OR 1.47, 95% CI 1.004 to 2.16 for those taking a BB, and OR 1.13, 95% CI 0.73 to 1.73 for those not taking a BB; for rs10033464, OR 1.89, 95% CI 1.22 to 2.93 for those taking preoperative a BB, and OR 1.04, 95% CI 0.65 to 1.65 for those not taking a BB). Both rs2200733 and rs10033464 were also associated with long-term AF (hazard ratio 1.32, 95% CI 1.05 to 1.67, and hazard ratio 1.28, 95% CI 1.00 to 1.66, respectively). Carriers of rs2200733 had increased long-term mortality (hazard ratio 1.57, 95% CI 1.10 to 2.24). These variants were not associated with postoperative or long-term stroke. In conclusion, variants in 4q25 are associated with an increased risk of postoperative or long-term AF and, possibly, mortality in whites undergoing coronary artery bypass grafting, and could potentially affect the choice of therapy used to decrease postoperative AF.

Long-term clinical outcome of coronary artery stenting or coronary artery bypass grafting in patients with multiple-vessel disease

OBJECTIVEnRecent large-scale observational studies have shown better outcomes after coronary artery bypass grafting than after angioplasty or stenting in patients with multiple-vessel disease. The time frames of these studies, however, include periods of varying behavior with respect to patient selection, stent technique and design, and medical therapy. Our objective was to examine long-term outcomes of coronary stenting and coronary artery bypass grafting, including those performed in the contemporary era of aggressive medical therapy.nnnMETHODSnWe examined in-hospital and long-term follow-up data from consecutive patients with multivessel coronary artery disease who underwent isolated initial revascularization by coronary stenting or coronary artery bypass grafting between 1995 and 2003. Cox proportional hazards modeling with propensity scoring and propensity-based case matching were used to compare long-term survival and correct for baseline differences between the populations.nnnRESULTSnA total of 6847 patients were studied (stenting 3917, coronary artery bypass grafting 2930). Each patient had 1 to 9 years of follow-up (median 3.5 years). Unadjusted long-term mortalities were similar for coronary artery bypass grafting and stenting (hazard ratio 1.1, 95% confidence interval 0.9-1.2, P = .21). Matched comparison of 3488 patients (1856 in each group) with similar likelihoods of undergoing coronary stenting or coronary artery bypass grafting, however, suggested that coronary artery bypass grafting provided better long-term survival (hazard ratio 0.7, 95% confidence interval 0.6-0.9; P = .004).nnnCONCLUSIONnDuring a 9-year period, in physician-selected patients with favorable demographic characteristics for both revascularization procedures, coronary artery bypass grafting was associated with better long-term survival than stent-assisted angioplasty.

Single Nucleotide Polymorphisms in Cholesteryl Ester Transfer Protein Gene And Recurrent Coronary Heart Disease or Mortality in Patients with Established Atherosclerosis

It is not known whether genetic variants in the cholesteryl ester transfer protein (CETP) gene are associated with recurrent coronary heart disease events or mortality in secondary prevention patients. Among 3,717 patients with acute coronary syndrome or coronary artery bypass grafting (CABG) enrolled in a prospective genetic registry, we evaluated whether CETP gene variants previously shown to be associated with reduced CETP activity and high-density lipoprotein cholesterol increase (A allele for both TaqIB [rs708272] and rs12149545) are associated with a reduction in recurrent myocardial infarction (MI), recurrent revascularization, or death. At 4.5xa0years of follow-up, 439 recurrent MI, 698 recurrent revascularizations, and 756 deaths occurred. Using an additive model of inheritance, the A allele for rs708272 was not associated with recurrent MI (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.78 to 1.17 for AG; HR 0.89, 95% CI 0.67 to 1.19 for AA; compared with GG genotype), recurrent revascularization (HR 1.13, 95% CI 0.95 to 1.33 for AG; HR 1.05, 95% CI 0.84 to 1.32 for AA), or mortality (HR 1.02, 95% CI 0.86 to 1.19 for AG; HR 1.11, 95% CI 0.91 to 1.37 for AA) in the overall cohort. Similar results were seen for the A allele for rs12149545. In the CABG subgroup, AG genotype for rs708272 was associated with an increased mortality (HR 1.38, 95% CI 1.06 to 1.79) compared with GG genotype. Results remained consistent using dominant model of inheritance. In conclusion, genetic CETP variants were not associated with recurrent MI or recurrent revascularization in overall cohort with a possible mortality increase in patients who underwent CABG.