Dong-A Kwon

Determinants of Surgical Outcome in Patients With Isolated Tricuspid Regurgitation

Background— We sought to identify preoperative predictors of clinical outcomes after surgery in patients with severe tricuspid regurgitation. Methods and Results— We prospectively enrolled 61 consecutive patients (54 women, aged 57±9 years) with isolated severe tricuspid regurgitation undergoing corrective surgery. Twenty-one patients (34%) were in New York Heart Association functional class II, 35 (57%) in class III, and 5 (9%) in class IV. Fifty-seven patients (93%) had previous history of left-sided valve surgery. Preoperative echocardiography revealed pulmonary artery systolic pressure of 41.5±8.7 mm Hg, right ventricular (RV) end-diastolic area of 35.1±9.0 cm2, and RV fractional area change of 41.3±8.4%. The median follow-up duration after surgery was 32 months (range, 12 to 70). Six of the 61 patients died before discharge; thus, operative mortality was 10%. Three of the 55 patients who survived surgery died during follow-up, and 6 patients required readmission because of cardiovascular problems. Thus, 46 patients (75%) remained event free at the end of follow-up. In the 54 patients who underwent 6-month clinical and echocardiographic follow-up, RV end-diastolic area decreased by 29%, with a corresponding 26% reduction in RV fractional area change. Thirty-three patients (61%) showed improved functional capacity after surgery. On multivariable Cox regression analysis, preoperative hemoglobin level (P<0.001) and RV end-systolic area (P<0.001) emerged as independent determinants of clinical outcomes. On receiver operating characteristic curve analysis, we found that RV end-systolic area <20 cm2 predicted event-free survival with a sensitivity of 73% and a specificity of 67%, and a hemoglobin level >11.3 g/dL predicted event-free survival with a sensitivity of 73% and a specificity of 83%. Conclusions— Timely correction of severe tricuspid regurgitation carries an acceptable risk and improves functional capacity. Surgery should be considered before the development of advanced RV systolic dysfunction and before the development of anemia.

Effect of celecoxib on restenosis after coronary angioplasty with a Taxus stent (COREA-TAXUS trial): an open-label randomised controlled study

BACKGROUND In-vitro and animal experiments have shown that the cyclo-oxygenase 2 inhibitor celecoxib can reduce formation of neointima within stents. We aimed to test whether celecoxib has similar effects in a clinical setting. METHODS In a randomised two-centre trial, we enrolled 274 patients who had angina pectoris or a positive stress test and who had native coronary artery lesions for which implantation of paclitaxel-eluting stents was feasible. All patients were given aspirin (100 mg daily) and clopidogrel (75 mg daily). 136 patients were randomly assigned to receive celecoxib (400 mg before the intervention, and 200 mg twice daily for 6 months after the procedure). The primary endpoint was late luminal loss on quantitative coronary angiography at 6 months after the intervention. Secondary endpoints were cardiac death, non-fatal myocardial infarction, and revascularisation of the target lesion. Analysis was done on a modified intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT00292721. FINDINGS At 6 months, mean in-stent late luminal loss was lower in the celecoxib group (0.49 mm, SD 0.47) than in the control group (0.75 mm, 0.60) (absolute difference 0.26 mm; 95% CI 0.12-0.40). Frequency of secondary outcomes at 6 months was also lower in the celecoxib group, mainly because of a reduced need for revascularisation of the target lesion. INTERPRETATION These data suggest that the adjunctive use of celecoxib for 6 months after stent implantation in patients with coronary artery disease is safe and can reduce the need for revascularisation of the target lesion.

Reasonable Duration of Clopidogrel Use After Drug-Eluting Stent Implantation in Korean Patients

Current guidelines recommend that clopidogrel be given to patients for 12 months after drug-eluting stent (DES) implantation. However, the evidence is insufficient to support the benefit of long-term clopidogrel therapy, especially in Asian patients. The aim of this study was to evaluate whether different durations of clopidogrel use might influence long-term outcomes after DES implantation. A total of 844 patients from 4 medical centers in Korea who had undergone successful DES implantation from November 2004 to April 2006 were enrolled. Patients who were event free at 6-month follow-up were divided into 2 groups by clopidogrel use (575 users, 163 nonusers) and followed. The end point was a composite of death, myocardial infarction, and stent thrombosis. During 1,056.4 patient-years of follow-up (median 2.02), there were 7 deaths, 3 myocardial infarctions, and 2 episodes of stent thrombosis. No significant differences in the primary end point were observed between clopidogrel users and nonusers (cumulative incidence 2.9% vs 2.8%, p = 0.578; adjusted hazard ratio 0.67, 95% confidence interval 0.16 to 2.77). In analysis with time-dependent covariates, the incidence rates of the primary end point during observation periods with and without clopidogrel were similar, although the effect estimates were broad (9.9 with and 10.6 without clopidogrel per 1,000 patient-years; adjusted hazard ratio 0.52, 95% confidence interval 0.09 to 3.17). Interestingly, the effect estimates from propensity score analyses, although they also had wide confidence intervals, were closer to the null than those from conventional Cox analyses. In conclusion, this cohort of Korean patients failed to show an absolute benefit of long-term clopidogrel therapy after DES implantation. The benefit of clopidogrel use beyond 6 months after DES implantation remains uncertain, and hence the decision to use long-term dual-antiplatelet therapy should be based on the risk factors of each patient.

Celecoxib Does Not Attenuate the Antiplatelet Effects of Aspirin and Clopidogrel in Healthy Volunteers

Background and Objectives The prevalence of arthritis, which is often treated with celecoxib, is high in patients with coronary artery disease. Furthermore, celecoxib has been reported to reduce restenosis after coronary stenting by inhibiting expression of the proto-oncogene Akt. A concern is that celecoxib increases thrombogenicity by inhibiting the synthesis of prostacyclin in endothelial cells. However, it is not known whether the administration of celecoxib will attenuate the antiplatelet effects of aspirin and clopidogrel, which are used after stenting. We addressed this gap in our knowledge. Subjects and Methods We recruited healthy volunteers (n=40) and randomized them into five subgroups (n=8 for each group: aspirin, celecoxib, aspirin+celecoxib, aspirin+clopidogrel, and aspirin+clopidogrel+celecoxib). Each subject received their medications for 6 days and blood samples were taken on day 0 and day 7. Celecoxib (200 mg twice a day), and/or aspirin (100 mg daily), and/or clopidogrel (75 mg daily) were administered. We compared platelet function among subgroups using light transmittance aggregometry and arachidonic acid metabolite assays. Results Celecoxib treatment alone did not significantly affect platelet aggregation. The reduction in adenosine diphosphase (ADP)-induced platelet aggregation by aspirin+clopidogrel was not affected by addition of celecoxib (31.3±6.9% vs. 32.4±12.2%, p=0.83). Inhibition of collagen-induced platelet aggregation by aspirin+clopidogrel was not affected by addition of celecoxib (47.6±13.4% vs. 51.6±3.7%, p=0.69). Drug-induced changes in prostacyclin and thromboxane levels did not differ among treatment groups. Conclusion Celecoxib treatment does not interfere with the antiplatelet effects of aspirin or clopidogrel, suggesting that celecoxib can be safely administered in combination with dual antiplatelet therapy in patients with coronary stenting without increased thrombogenicity.

Response to Letters Regarding Article “Determinants of Surgical Outcome in Patients With Isolated Tricuspid Regurgitation”

We thank Drs Raikhelkar and Scurlock for their thoughtful review of our article.1 As pointed out, the pathogenesis of tricuspid regurgitation was functional late after left-sided valve surgery in most of our study subjects, and thus our findings may not be directly applicable in tricuspid regurgitation patients with other organic valve diseases. We agree that this is an important limitation of our study. However, because we prospectively enrolled consecutive patients, we believe our data represent the real patient population in tertiary referral center. Further long-term study is needed to determine predictors of …