Kyoung-Min Park

Late stent malapposition after drug-eluting stent implantation: an intravascular ultrasound analysis with long-term follow-up.

Background— Late stent malapposition (LSM) after drug-eluting stent (DES) implantation has not been evaluated sufficiently in real-world practice. Methods and Results— We evaluated the incidence, mechanisms, predictors, and long-term prognosis of LSM after DES implantation in 557 patients (705 native lesions; sirolimus-eluting stent in 538 lesions and paclitaxel-eluting stent in 167 lesions) in whom intravascular ultrasound was performed at index and 6-month follow-up. LSM occurred in 82 patients with 85 lesions (12.1% overall, 95% CI 9.7% to 14.5%, 71 lesions (13.2%) in sirolimus-eluting stents and 14 lesions [8.4%] in paclitaxel-eluting stents, P=0.12]; the incidence was 25.0% (4/16) after directional coronary atherectomy before stenting, 27.5% (14/51) in chronic total occlusion lesions, and 31.8% (7/22) after primary stenting in acute myocardial infarction (P=0.13, P<0.001, and P=0.001, respectively, versus elective stenting with conventional balloon predilation, 9.7% [60/616]). There was an increase of external elastic membrane area (from 17.1±3.6 to 21.4±4.8 mm2, P<0.001) that was greater than the increase in plaque area (from 9.3±2.5 to 10.5±2.7 mm2, P<0.001). Independent predictors of LSM were total stent length, primary stenting in acute myocardial infarction, and chronic total occlusion lesions. Except for 1 death in the non-LSM group, there were no major adverse cardiac events in either LSM or non-LSM patients during a mean 10-month follow-up after detection of LSM. Conclusions— LSM occurs in 12% of cases after DES implantation. The predictors of LSM are total stent length, primary stenting in acute myocardial infarction, and chronic total occlusion lesions. LSM after DES implantation was not associated with any major adverse cardiac events during a subsequent 10-month (mean) follow-up.

Percutaneous Mitral Valvuloplasty Versus Surgical Treatment in Mitral Stenosis With Severe Tricuspid Regurgitation

Background— The persistence of significant tricuspid regurgitation (TR) after percutaneous mitral valvuloplasty (PMV) is known to be an independent predictor of adverse outcome in mitral stenosis (MS). However, it remains unclear whether mitral valve (MV) surgery combined with surgical correction of TR is the better treatment option than PMV in patients with severe MS and severe functional TR. Methods and Results— We included a total of 92 consecutive patients (18 men, age 49±13 years) with severe MS and severe functional TR, who were potential candidates for PMV from 1997 to 2005, and the exclusion criteria were defined as the presence of left atrial thrombi, mitral regurgitation ≥grade 3, echo score >10, and left ventricular ejection fraction (EF) <35%. PMV was performed on 48 patients (PMV group), and MV surgery combined with tricuspid valve (TV) repair was performed on 44 patients (TVP group). The clinical events were defined as death, repeat surgical or percutaneous intervention, and readmission because of heart failure. There were no significant differences between the 2 groups in terms of gender, baseline EF, and baseline severity of pulmonary hypertension, but patients in the TVP group were older and had a higher echo score and a higher incidence of atrial fibrillation than those in the PMV group. During follow-up of 57±35 months, 2 deaths occurred in the TVP group, and there were 2 deaths, 7 cases of heart failure requiring surgical intervention in the PMV group. The difference of event rates between the 2 groups showed borderline significance (P=0.05), but no difference in mortality was observed. The estimated actuarial 7-year event-free survival rate was 77±8% in the PMV group and 95±3% in the TVP group. Severe TR was improved to mild or absent TR in 43 (98%) patients in the TVP group, and this was significantly higher than in the PMV group (22/48, 46%; P<0.001). In the TVP group, the right ventricle (RV) size was significantly decreased in 18 (90%) patients among 20 patients with preoperative significant RV enlargement. On stepwise multivariate logistic regression analysis, TVP group and baseline sinus rhythm were independent predictors for improvement of TR (P<0.001). Conclusions— TV repair combined with MV surgery was related to better clinical outcomes than PMV alone, and we recommend that this surgical option should be considered preferentially in severe MS with severe functional TR, especially if atrial fibrillation or enlarged RV is associated.

Diagnostic approach and treatment strategy in tachycardia-induced cardiomyopathy.

Due to the absence of differential guidelines for heart failure with tachyarrhythmia, it is difficult to diagnose tachycardia‐induced cardiomyopathy (TIC) at the initial visit. Furthermore, clinical outcomes of rate versus rhythm control in TIC are unclear.

Comparison of the effectiveness of sirolimus‐ and paclitaxel‐eluting stents for small coronary artery lesions

Background: The sirolimus‐eluting stent (SES) and the paclitaxel‐eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes. Methods: The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (≤≤2.75 mm) that were treated with either the SES (156 lesions) or the PES (89 lesions). Six‐month angiographic restenosis rates and the 9‐month target lesion revascularization (TLR) rates were compared between the two groups. Results: In terms of baseline clinical and angiographic parameters, the two groups well matched together. Six‐month angiographic follow‐up was performed on 170 patients (86.3%), comprising 135 SES lesions (86.5%) and 76 PES lesions (85.4%). At 6‐month angiographic follow‐up, the late lumen loss was less in the SES group than in the PES group (0.29 ± 0.42 vs. 0.69 ± 0.63 mm, P < 0.01). Therefore, the SES group showed a lower rate of angiographic restenosis than the PES group (6.7% vs. 27.7%, P < 0.01). At 9 months there were no deaths or myocardial infarctions in either group. The 9‐month TLR rate was lower in the SES group than in the PES group (3.3% vs. 14.4%, P < 0.01). The Kaplan‐Meier estimate of freedom from TLR at 9 months was 96.7% for the SES patients and 86.5% for the PES patients (P < 0.01). Conclusions: The SES treatment may be superior to the PES treatment in terms of long‐term clinical and angiographic outcomes in patients with small coronary artery lesions.

Electrophysiologic Results After Thoracoscopic Ablation for Chronic Atrial Fibrillation

BACKGROUND Thoracoscopic ablation for lone atrial fibrillation (AF) has evolved rapidly in the past decade. We investigated the electrophysiologic results and midterm durability of totally thoracoscopic ablation in patients with lone persistent AF. METHODS Seventy-nine consecutive patients with paroxysmal AF (8 patients, 10.1%), persistent AF (17 patients, 21.5%), and long-standing persistent AF (54 patients, 68.3%) were prospectively enrolled. Thoracoscopic ablation consisted of a bilateral closed-chest approach to performing pulmonary isolation (a box lesion), ganglionated plexus ablation, division of the Marshall ligament, and left atrial auricle resection. An electrophysiologic study was performed 5 days after the surgical procedure in 61 patients (77%). Freedom from AF was assessed with electrocardiograms or Holter monitoring every 3 months, with a mean follow-up of 12.1 (maximum, 28) months. RESULTS No deaths or conversion to cardiopulmonary bypass occurred. During electrophysiologic study, 28 residual pulmonary vein potentials were observed in 15 patients (19%). Out of a total of 28 gaps, 20 (71%) were located in the superior and inferior ridges of pulmonary veins. Six gaps (21%) were detected in the carina of pulmonary veins. The mitral isthmus was ablated in 2 patients (7%). Freedom from AF at 2 years was 92.6 ± 3.3%. Freedom from cardiac-related events at 2 years was 74.7 ± 6.0%. Cox regression analysis demonstrated that the predictors of atrial arrhythmias were old age, hypertension, and left atrial volume index. CONCLUSIONS Thoracoscopic ablation followed by electrophysiologic confirmation was safe and provided excellent midterm durability in patients with AF. However, the incidence of residual potentials around the pulmonary veins was not negligible.

Enterococcus avium bacteremia: a 12-year clinical experience with 53 patients

Because Enterococcus avium is rarely isolated from blood cultures, little is known about the clinical features and outcomes of bacteremia caused by this organism, formerly called “group Q streptococcus”. We retrospectively evaluated the clinical features and outcomes of patients with clinically significant bacteremia caused by E. avium presenting at a tertiary-care hospital in Korea between February 1997 and February 2009. We identified 53 patients over the 12-year period; of these, 27 (50.9%) had biliary and 13 (24.5%) had intra-abdominal E. avium infections. Thirty-six (67.9%) of the episodes were polymicrobial. Thirty-three (62.3%) episodes were nosocomial bloodstream infections and resistance to vancomycin was not observed. The crude mortality rate was 24.5% (13/53), and the E. avium bacteremia-related mortality rate was 11.3% (6/53). Multivariate analysis showed that underlying rapidly fatal or ultimately fatal disease (adjusted odds ratio [AOR], 6.92; 95% confidence interval [CI], 1.56–30.65; P = 0.011) and inadequate antimicrobial therapy (AOR, 7.29; CI, 1.27–41.93; P = 0.026) were independent risk factors for mortality. In summary, bacteremia due to E. avium was commonly of biliary or intraabdominal origin and was often associated with polymicrobial bacteremia. The crude mortality rate was considerable. Severe underlying conditions and inadequate antimicrobial therapy were significant and independent risk factors for crude patient mortality.

Long-term Prognosis of Paroxysmal Atrial Fibrillation and Predictors for Progression to Persistnt or Chronic Atrial Fibrillation in the Korean Population

Little is known about the long-term prognosis of or predictors for the different clinical types of atrial fibrillation (AF) in Korean populations. The aim of this study was to validate a risk stratification to assess the probability of AF progression from paroxysmal AF (PAF) to persistent AF (PeAF) or permanent AF. A total of 434 patients with PAF were consecutively enrolled (mean age; 71.7 ± 10.7 yr, 60.6% male). PeAF was defined as episodes that are sustained > 7 days and not self-terminating, while permanent AF was defined as an ongoing long-term episode. Atrial arrhythmia during follow-up was defined as atrial premature complex, atrial tachycardia, and atrial flutter. During a mean follow-up of 72.7 ± 58.3 months, 168 patients (38.7%) with PAF progressed to PeAF or permanent AF. The mean annual AF progression was 10.7% per year. In univariate analysis, age at diagnosis, body mass index, atrial arrhythmia during follow-up, left ventricular ejection fraction, concentric left ventricular hypertrophy, left atrial diameter (LAD), and severe mitral regurgitation (MR) were significantly associated with AF progression. In multivariate analysis, age at diagnosis (P = 0.009), atrial arrhythmia during follow-up (P = 0.015), LAD (P = 0.002) and MR grade (P = 0.026) were independent risk factors for AF progression. Patients with younger age at diagnosis, atrial arrhythmia during follow-up, larger left atrial chamber size, and severe MR grade are more likely to progress to PeAF or permanent AF, suggesting more intensive medical therapy with close clinical follow-up would be required in those patients.

Efficacy of Dronedarone Versus Propafenone in the Maintenance of Sinus Rhythm in Patients With Atrial Fibrillation After Electrical Cardioversion

PURPOSE Our objective was to compare the efficacy of dronedarone and propafenone in maintaining sinus rhythm in patients with atrial fibrillation (AF) after electrical cardioversion. METHODS In this single-center, open-label, randomized trial, we randomly assigned patients with AF after electrical cardioversion to receive dronedarone 400 mg BID or propafenone 150 mg TID. Follow-up clinical evaluations were conducted at 1, 2, 3, and 6 months of treatment. The primary end point was the time to the first recurrence of AF. FINDINGS A total of 98 patients were enrolled (79 men; mean age, 59.2 years; n = 49 per group). The median times to first recurrence of AF were 31 days in the dronedarone group and 32 days in the propafenone group (P = 0.715). The median (interquartile range) ventricular rates at first recurrence of AF were 76.5 (67.3-86.5) beats/min in the dronedarone group and 83.0 (71.0-96.0) beats/min in the propafenone group (P = 0.059). IMPLICATIONS Dronedarone and propafenone had similar efficacies in maintaining sinus rhythm in patients with AF after electrical cardioversion. The ventricular rate at the first recurrence of AF was numerically but not statistically significantly lower in the dronedarone group than in the propafenone group. ClinicalTrials.gov identifier: NCT01991119.

Electrical PR Interval Variation Predicts New Occurrence of Atrial Fibrillation in Patients With Frequent Premature Atrial Contractions

AbstractAtrial fibrillation (AF) is associated with the autonomic nervous system (ANS), and fluctuation of autonomic tone is more prominent in patients with AF. As autonomic tone affects the heart rate (HR), and there is an inverse relationship between HR and PR interval, PR interval variation could be greater in patients with AF than in those without AF. The purpose of this study was to investigate the correlation between PR interval variation and new-onset AF in patients with frequent PACs.We retrospectively enrolled 207 patients with frequent PACs who underwent electrocardiographs at least 4 times during the follow-up period. The PR variation was calculated by subtracting the minimum PR interval from the maximum PR interval. The outcomes were new occurrence of AF and all-cause mortality during the follow-up period.During a median follow-up of 8.3 years, 24 patients (11.6%) developed new-onset AF. Univariate analysis showed that prolonged PR interval (PR interval > 200 ms, P = 0.021), long PR variation (PR variation > 36.5 ms, P = 0.018), and PR variation (P = 0.004) as a continuous variable were associated with an increased risk of AF. Cox regression analysis showed that prolonged PR interval (hazard ratio = 3.321, 95% CI 1.064–10.362, P = 0.039) and PR variation (hazard ratio = 1.013, 95% CI 1.002–1.024, P = 0.022) were independent predictors for new-onset AF. However, PR variation and prolonged PR interval were not associated with all-cause mortality (P = 0.465 and 0.774, respectively).PR interval variation and prolonged PR interval are independent risk factors for new-onset AF in patients with frequent PACs. However we were unable to determine a cut-off value of PR interval variation for new-onset AF.

Correlation of Cardiac Markers and Biomarkers With Blood Pressure of Middle-Aged Marathon Runners.

Runners with exercise‐induced high blood pressure have recently been reported to exhibit higher levels of cardiac markers, vasoconstrictors, and inflammation. The authors attempted to identify correlations between exercise‐related personal characteristics and the levels of biochemical/cardiac markers in marathon runners in this study. Forty healthy runners were enrolled. Blood samples were taken both before and after finishing a full marathon. The change in each cardiac/biochemical marker over the course of the marathon was determined. All markers were significantly (P<.001) increased immediately after the marathon (creatine kinase‐MB [CK‐MB]: 7.9±2.7 ng/mL, cardiac troponin I (cTnI): 0.06±0.10ng/mL, N‐terminal pro–B‐type natriuretic peptide (NT‐proBNP): 95.7±76.4, endothelin‐1: 2.7±1.16, high‐sensitivity C‐reactive protein [hs‐CRP]: 0.1±0.09, creatine kinase [CK]: 315.7±94.0, lactate dehydrogenase [LDH]: 552.8±130.3) compared with their premarathon values (CK‐MB: 4.3±1.3, cTnI: 0.01±0.003, NT‐proBNP: 27.6±31.1, endothelin‐1: 1.11±0.5, hs‐CRP: 0.06±0.07, CK: 149.2±66.0, LDH: 399±75.1). In middle‐aged marathon runners, factors related to increased blood pressure were correlated with marathon‐induced increases in cTnI, NT‐proBNP, endothelin‐1, and hs‐CRP. These correlations were observed independent of running history, records of finishing, and peak oxygen uptake.