Long-term outcomes of left atrial appendage occlusion in patients with atrial fibrillation and end stage renal disease.

OBJECTIVE: In patients with atrial fibrillation (AF) and end-stage renal disease (ESRD), oral anticoagulants are contraindicated, and left atrial appendage occlusion (LAAO) is an alternative treatment. However, the efficacy of thromboembolic prevention using LAAO in these patients has rarely been reported in Asian populations. To our knowledge, this is the first long-term LAAO study in patients with AF undergoing dialysis in Asia. METHODS: In this study, 310 patients (179 men) with a mean age of 71.3 ± 9.6 years and mean CHA2DS2-VASc 4.2 ± 1.8 were consecutively enrolled at multiple centers in Taiwan. The outcomes of 29 patients with AF and ESRD undergoing dialysis who underwent LAAO were compared to those without ESRD. The primary composite outcomes were stroke, systemic embolization, or death. RESULTS: No difference in mean CHADS-VASc score was noted between patients with versus without ESRD (4.1 ± 1.8 vs. 4.6 ± 1.9, p = 0.453). After a mean follow-up of 38 ± 16 months, the composite endpoint was significantly higher in patients with ESRD (hazard ratio, 5.12 [1.4-18.6]; p = 0.013) than in those without ESRD after LAAO therapy. Mortality was also higher in patients with ESRD (hazard ratio, 6.6 [1.1-39.7]; p = 0.038). The stroke rate was numerically higher in patients with versus without ESRD, but the difference was not statistically significant (hazard ratio, 3.2 [0.6-17.7]; p = 0.183). Additionally, ESRD was associated with device-related thrombosis (odds ratio, 6.15; p = 0.047). CONCLUSION: Long-term outcomes of LAAO therapy may be less favorable in patients with AF undergoing dialysis, possibly because of the poor condition of patients with ESRD.

Improving lung function capacity in patients with chronotropic incompetence using closed loop stimulation: A randomized crossover study.

BACKGROUND: Chronotropic incompetence (CI) severely limits exercise tolerance due to impaired heart rate responses. This study investigated whether pacemaker with closed-loop stimulation (DDD-CLS) pacing, which provides rate acceleration in response to exertion, could enhance lung function and cardiopulmonary capacity compared pacemaker without CLS pacing in patients with CI. METHODS: This randomized crossover trial included 32 patients with CI who were compared to each CLS and DDD pacing over 2 months. Spirometry was used to assess the forced vital capacity (FVC). Cycling-based cardiopulmonary exercise testing (CPET) measured peak oxygen uptake (peak VO2). RESULTS: DDD-CLS pacing yielded significantly higher FVC (2.2 ± 0.8 L) versus DDD pacing (2.0 ± 0.7 L), p = 0.036, a 3.2% improvement. Moreover, those in the DDD-CLS mode showed a significantly higher FEV1 of 1.8 ± 0.6 L compared to the DDD mode of 1.7 ± 0.5 L (p = 0.03). Compared with DDD pacing, DDD-CLS pacing also achieved superior peak VO2 (14.9 ± 4.0 vs 12.2 ± 3.7 mlO2/kg/min, p < 0.001) and peak heart rate (106.9 ± 9.7 vs 98.3 ± 19.8 bpm, p = 0.013). DDD-CLS and DDD pacing modes showed significant correlations between FVC and peak VO2 and between peak VO2 and peak heart rate during CPET. CONCLUSIONS: Compared with DDD mode, DDD-CLS pacing provided physiological chronotropic support to improve cardiopulmonary function during exertion, which enhanced lung capacity in patients with CI.

Enhancement of bicycle exercise capacity in patients with chronotropic incompetence through closed-loop stimulation: a randomized crossover trial.

AIMS: This study aimed to investigate the effectiveness of closed-loop stimulation (CLS) pacing compared with the traditional DDD mode in patients with chronotropic incompetence (CI) using bicycle-based cardiopulmonary exercise testing (CPET). METHODS AND RESULTS: This single-centre, randomized crossover trial involved 40 patients with CI. Patients were randomized to receive either DDD-CLS or DDD mode pacing for 2 months, followed by a crossover to the alternative mode for an additional 2 months. Bicycling-based CPET was conducted at the 3- and 5-month follow-up visits to assess exercise capacity. Other cardiopulmonary exercise outcome measures and health-related quality of life (QoL) were also assessed. DDD-CLS mode pacing significantly improved exercise capacity, resulting in a peak oxygen uptake (14.8 ± 4.0 vs. 12.0 ± 3.6 mL/kg/min, P < 0.001) and oxygen uptake at the ventilatory threshold (10.0 ± 2.2 vs. 8.7 ± 1.8 mL/kg/min, P < 0.001) higher than those of the DDD mode. However, there were no significant differences in other cardiopulmonary exercise outcome measures such as ventilatory efficiency of carbon dioxide production slope, oxygen uptake efficiency slope, and end-tidal carbon dioxide between the two modes. Patients in the DDD-CLS group reported a better QoL, and 97.5% expressed a preference for the DDD-CLS mode. CONCLUSION: DDD-CLS mode pacing demonstrated improved exercise capacity and QoL in patients with CI, highlighting its potential as an effective pacing strategy for this patient population.

Peri-device leakage not CHA2DS2-VASc is associated with post-left atrial appendage closure cardiovascular event.

OBJECTIVE: In patients with non-valvular atrial fibrillation (NVAF), the left atrial appendage occluder (LAAO) is an alternative treatment for stroke prevention. However, thromboembolic event still occur, and the predictors are unknown. METHODS: The first Asian long-term follow-up study consisted of 308 patients with mean age 71.9±9.5 years, mean CHA2DS2-VASc 4.1 ± 1.8 since 2013. Primary outcome was defined as any type of ischemic stroke/transient ischemic attack (TIA), systemic embolization and cardiovascular death. RESULTS: There was no procedural-related TIA or stroke. After a mean follow-up of 38±16 months, the ischemic stroke/TIA rate was 1.9 and cardiovascular death rate 0.3 per 100 patient-year. The rate of peri-device leak (PDL) was 11.9% and device-related thrombus (DRT) 2.6%. In the multivariable analyses, PDL was the only independent predictor of stroke/TIA (hazard ratio 5.5, p=0.008). CHA2DS2-VASc score, prior history of stroke, DRT and post-procedural anti-thrombotic regimen/duration were not associated with outcomes. Implantation of Watchman was associated with PDL (odds ratio 4.35, p=0.001). CONCLUSIONS: PDL is the only independent predictor of post-LAAO stroke. The risk of stroke for patients with NVAF may be controllable after LAA is occluded, because PDL is preventable and treatable.

Cyclic stretching boosts microRNA-499 to regulate Bcl-2 via microRNA-208a in atrial fibroblasts.

MicroRNAs that modulate transcription can regulate other microRNAs and are also up-regulated under pathological stress. MicroRNA-499 (miR-499), microRNA-208a (miR-208a) and B-cell lymphoma 2 (Bcl-2) play roles in cardiovascular diseases, such as direct reprogramming of cardiac fibroblast into cardiomyocyte and cardiomyocyte apoptosis. Whether miR208a, miR499 and Bcl-2 were critical regulators in cardiac fibroblast apoptosis under mechanical stretching conditions in human cardiac fibroblasts-adult atrial (HCF-aa) was investigated. Using negative pressure, HCF-aa grown on a flexible membrane base were cyclically stretched to 20% of their maximum elongation. In adult rats, an aortocaval shunt was used to create an in vivo model of volume overload. MiR208a was up-regulated early by stretching and returned to normal levels with longer stretching cycles, whereas the expression of miR499 and Bcl-2 was up-regulated by longer stretching times. Pre-treatment with antagomir-499 reversed the miR-208a down-regulation, whereas Bcl-2 expression could be suppressed by miR-208a overexpression. In the HCF-aa under stretching for 1 h, miR-499 overexpression decreased pri-miR-208a luciferase activity; this inhibition of pri-miR-208a luciferase activity with stretching was reversed when the miR-499-5p binding site in pri-miR-208a was mutated. The addition of antagomir-208a reversed the Bcl-2-3'UTR suppression from stretching for 1 h. Flow cytometric analysis revealed that pre-treatment with miR-499 or antagomir-208a inhibited cellular apoptosis in stretched HCF-aa. In hearts with volume overload, miR-499 overexpression inhibited myocardial miR-208a expression, whereas Bcl-2 expression could be suppressed by the addition of miR-208a. In conclusion, miR-208a mediated the regulation of miR-499 on Bcl-2 expression in stretched HCF-aa and hearts with volume overload.

Prognostic impact of renal dysfunction on embolic stroke of undetermined source-Role beyond CHA2 DS2 -VASc score: Results from Taiwan Stroke Registry.

BACKGROUND AND PURPOSE: The CHA2 DS2 -VASc score has immense prognostic value in patients with embolic stroke of undetermined source (ESUS). We aimed to determine the usefulness of advanced renal dysfunction and its addition to the CHA2 DS2 -VASc score in improving predictive accuracy. METHODS: In total, 3775 ESUS patients were enrolled from a nationwide hospital-based prospective study. Advanced renal dysfunction was defined as estimated glomerular filtration rate <30 ml/min per 1.73 m2 or patients under dialysis. Clinical outcomes included recurrent stroke and 1-year all-cause mortality. Poor functional outcome was defined as a modified Rankin Scale >2 at first-, third-, and sixth-month post-stroke. The renal (R)-CHA2 DS2 -VASc score was derived by including advanced renal dysfunction in the CHA2 DS2 -VASc score. Risk stratification improvement after including advanced renal dysfunction was assessed using C statistic, integrated discrimination improvement (IDI), and category-free net reclassification index (NRI). RESULTS: After adjusting for confounding factors and CHA2 DS2 -VASc score, advanced renal dysfunction showed significant associations with all-cause mortality (HR: 2.88, 95% CI: 1.92-4.34) and poor functional outcome at third- (OR: 2.69, 95% CI: 1.47-4.94) and sixth-month post-stroke (OR: 2.67, 95% CI: 1.47-4.83). IDI and NRI showed that incorporating advanced renal dysfunction significantly improved risk discrimination over the original CHA2 DS2 -VASc score. R-CHA2 DS2 -VASc score ≥2 increased risk by 1.94-fold (95% CI: 1.15-3.27) for all-cause mortality, and ≥4 increased risk by 1.62-fold (95% CI: 1.05-2.50) of poor functional outcome at third-month post-stroke and by 1.81-fold (95% CI: 1.19-2.75) at sixth-month post-stroke. CONCLUSIONS: Advanced renal dysfunction was significantly associated with clinical and functional outcomes in ESUS patients and may improve prognostic impact of the CHA2 DS2 -VASc score.

Chrysin boosts KLF2 expression through suppression of endothelial cell-derived exosomal microRNA-92a in the model of atheroprotection.

PURPOSE: Atherosclerosis and its related clinical complications are the leading cause of death. MicroRNA (miR)-92a in the inflammatory endothelial dysfunction leads to atherosclerosis. Krüppel-like factor 2 (KLF2) is required for vascular integrity and endothelial function maintenance. Flavonoids possess many biological properties. This study investigated the vascular protective effects of chrysin in balloon-injured carotid arteries. MATERIALS AND METHODS: Exosomes were extracted from human coronary artery endothelial cell (HCAEC) culture media. Herb flavonoids and chrysin were the treatments in these atheroprotective models. Western blotting and real-time PCRs were performed. In situ hybridization, immunohistochemistry, and immunofluorescence analyses were employed. RESULTS: MiR-92a increased after balloon injury and was present in HCAEC culture media. Chrysin was treated, and significantly attenuated the miR-92a levels after balloon injury, and similar results were obtained in HCAEC cultures in vitro. Balloon injury-induced miR-92a expression, and attenuated KLF2 expression. Chrysin increased the KLF2 but reduced exosomal miR-92a secretion. The addition of chrysin and antagomir-92a, neointimal formation was reduced by 44.8 and 49.0% compared with balloon injury after 14 days, respectively. CONCLUSION: Chrysin upregulated KLF2 expression in atheroprotection and attenuated endothelial cell-derived miR-92a-containing exosomes. The suppressive effect of miR-92a suggests that chrysin plays an atheroprotective role. Proposed pathway for human coronary artery endothelial cell (HCAEC)-derived exosomes induced by chrysin to suppress microRNA (miR)-92a expression and counteract the inhibitory effect of miR-92a on KLF2 expression in HCAECs. This provides an outline of the critical role of the herbal flavonoid chrysin, which may serve as a valuable therapeutic supplement for atheroprotection.

Comparison of Arrhythmia Detection by 24-Hour Holter and 14-Day Continuous Electrocardiography Patch Monitoring.

BACKGROUND: Although 24-hour Holter monitoring is routinely used for patients with suspected paroxysmal arrhythmia, its sensitivity in detecting such arrhythmias is insufficient. METHODS: We compared a 14-day electrocardiography (ECG) monitor patch - a single-use, noninvasive, waterproof, continuous monitoring patch - with a 24-hour Holter monitor in 32 consecutive patients with suspected arrhythmia. RESULTS: The 14-day ECG patch was well tolerated, and its rates of detection of relevant arrhythmias on days 1, 3, 7, and 14 were 13%, 28%, 47%, and 66%, respectively. The detection rate of paroxysmal arrhythmias was significantly higher for the 14-day ECG patch than for the 24-hour Holter monitor (66% vs. 9%, p < 0.001). Among the 32 patients, 202 atrial fibrillation or atrial flutter episodes were detected in 6 patients (22%) with the 14-day ECG patch; however, only 1 atrial fibrillation episode was detected in a patient (3%, p < 0.05) with the 24-hour Holter monitor. Other clinically relevant arrhythmias recorded on the 14-day ECG patch included 21 (65.5%) episodes of supraventricular tachycardia, 2 (6.3%) long pause, and 2 (6.3%) ventricular arrhythmias. The mean dermal response score immediately after removal of the 14-day ECG patch from the patients was 0.64, which indicated minimal erythema. CONCLUSIONS: The 14-day ECG patch was well tolerated and allowed for longer continuous monitoring than the 24-hour Holter monitor, thus resulting in improved clinical accuracy in the detection of paroxysmal arrhythmias. Future studies should examine the long-term effectiveness of 14-day ECG patches for managing selected patients.

Effect of atorvastatin on cardiomyocyte hypertrophy through suppressing MURC induced by volume overload and cyclic stretch.

MURC (muscle-restricted coiled-coil protein) is a hypertrophy-related gene. Hypertrophy can be induced by mechanical stress. The purpose of this research was to investigate the hypothesis that MURC mediates hypertrophy in cardiomyocytes under mechanical stress. We used the in vivo model of an aortocaval shunt (AV shunt) in adult Wistar rats to induce myocardial hypertrophy. We also used the in vitro model of cyclic stretch in rat neonatal cardiomyocytes to clarify MURC expression and the molecular regulation mechanism. The flexible membrane culture plate seeding with cardiomyocytes Cardiomyocytes seeded on a flexible membrane culture plate were stretched by vacuum pressure to 20% of maximum elongation at 60 cycles/min. AV shunt induction enhanced MURC protein expression in the left ventricular myocardium. Treatment with atorvastatin inhibited the hypertrophy induced by the AV shunt. Cyclic stretch markedly enhanced MURC protein and mRNA expression in cardiomyocytes. Addition of extracellular-signal-regulated kinase (ERK) inhibitor PD98059, ERK small interfering RNA (siRNA), angiotensin II (Ang II) antibody and atorvastatin before stretch, abolished the induction of MURC protein. An electrophoretic mobility shift assay showed that stretch enhanced the DNA binding activity of serum response factor. Stretch increased but MURC mutant plasmid, ERK siRNA, Ang II antibody and atorvastatin reversed the transcriptional activity of MURC induced by stretch. Adding Ang II to the cardiomyocytes also induced MURC protein expression. MURC siRNA and atorvastatin inhibited the hypertrophic marker and protein synthesis induced by stretch. Treatment with atorvastatin reversed MURC expression and hypertrophy under volume overload and cyclic stretch.

Real-World Experience with Idarucizumab to Reverse Anticoagulant Effect in Dabigatran-Treated Patients: Report of 11 Cases from Taiwan.

BACKGROUND: This study aims to observe the effectiveness and safety of idarucizumab in dabigatran-treated patients with severe bleeding or requiring surgery in Taiwan. METHODS AND RESULTS: In Taiwan, 11 dabigatran-treated patients developed severe bleeding, fracture that needed surgery, and acute ischemic stroke requiring thrombolysis. These patients were treated with idarucizumab and obtained adequate hemostasis. Our experiences reconfirmed the efficacy and safety of idarucizumab in Asian patients. CONCLUSIONS: Idarucizumab improves safety in dabigatran-treated patients. Continued education about the availability and appropriate use of idarucizumab is necessary in Asia.

Coronary artery aneurysm after implantation of a bioresorbable vascular scaffold: Case report and literature review.

A 55-year-old man underwent successful percutaneous coronary intervention for the middle left circumflex artery with a 3.5 × 28-mm bioresorbable vascular scaffold (BVS). At 18 months, follow-up coronary angiography showed ectatic change with aneurysm formation over the BVS. Optical coherence tomography revealed absence of strut continuity at the aneurysm site, in the middle of the BVS. A literature review identified nine patients with intrascaffold aneurysm, including the present patient, which developed 6-32 months after BVS implantation. Of these nine patients, four underwent percutaneous coronary intervention for chronic total occlusion. The pathogenesis of coronary artery aneurysm is multifactorial. Most patients receive no further intervention, but long-term dual antiplatelet therapy is sometimes prescribed in conjunction with regular follow-up. © 2017 Wiley Periodicals, Inc.

Atorvastatin alleviates cardiomyocyte apoptosis by suppressing TRB3 induced by acute myocardial infarction and hypoxia.

BACKGROUND/PURPOSE: TRB3 (tribbles 3), an apoptosis-regulated gene, increases during endoplasmic reticulum stress. Hypoxia can induce inflammatory mediators and apoptosis in cardiomyocytes. However, the expression of TRB3 in cardiomyocyte apoptosis under hypoxia is not thoroughly known. We investigated the regulation mechanism of TRB3 expression and apoptosis induced by hypoxia in cardiomyocytes. METHODS: An in vivo model of acute myocardial infarction (AMI) was applied in adult Wistar rats to induce myocardial hypoxia. Rat neonatal cardiomyocytes were subjected to 2.5% O2 to induce hypoxia. RESULTS: The expression of TRB3 was evaluated in cultured rat neonatal cardiomyocytes subjected to hypoxia. Hypoxia significantly enhanced TRB3 protein and mRNA expression. Adding c-jun N-terminal kinase (JNK) inhibitor SP600125, JNK small interfering RNA (siRNA), tumor necrosis factor-α (TNF-α) antibody, and atorvastatin 30 minutes before hypoxia reversed the induction of TRB3 protein. A gel-shift assay showed the DNA-binding activity of growth arrest and DNA damage-inducible gene 153 (GADD153), which increased after hypoxia. Hypoxia increased, whereas the TRB3-mut plasmid, SP600125, and TNF-α antibody abolished the hypoxia-induced TRB3 promoter activity. Hypoxia increased the secretion of TNF-α from cardiomyocytes. Exogenous administration of TNF-α recombinant protein to the cardiomyocytes without hypoxia increased TRB3 protein expression, similar to that observed after hypoxia. Hypoxia-induced cardiomyocyte apoptosis is inhibited by TRB3 siRNA, the TNF-α antibody, and atorvastatin. Atorvastatin reduced the TRB3 expression and cardiomyocyte apoptosis induced by AMI. Hypoxia induces TRB3 through TNF-α, JNK, and the GADD153 pathway. CONCLUSION: Treatment of atorvastatin inhibits the expression of TRB3 and cardiomyocyte apoptosis induced by AMI and hypoxia.

Prognostic impact of renal dysfunction in patients with acute coronary syndrome-role beyond the CHA2 DS2 -VASc score: Data from Taiwan acute coronary syndrome full spectrum registry.

AIM: CHA2 DS2 -VASc score has been proven to have great prognostic value in patients with acute coronary syndrome (ACS). We aimed to determine whether the addition of renal dysfunction in the CHA2 DS2 -VASc score would improve the prognostic impact of the scoring system to predict prognosis among ACS patients. METHODS: A total of 3031 ACS patients were prospectively enrolled at 39 hospitals and followed for 1 year. The patients were divided into three groups based on estimated glomerular filtration rate (eGFR) (group 1, eGFR>90; group 2, eGFR between 60 and 90; and group 3, eGFR<60 mL/min per 1.73 m(2) ). The occurrence of subsequent myocardial infarction (MI), stroke, or death was recorded. RESULTS: As renal function progressively decreased from group 1 to 3, the patients were, respectively older and had higher incidence of comorbidity, worse Killip classification, and less evidence-based medical therapies. The rate of subsequent MI, stroke or death increased from 3.4% in group 1 to 7.4% in group 2 and 17.2% in group 3 (P < 0.001). Renal dysfunction (eGFR<60 mL/min per 1.73 m(2) ) and CHA2 DS2 -VASc scores were both significant predictors of adverse events in multivariable regression analyses. Renal dysfunction can further stratify patients with CHA2 DS2 -VASc score of 0 or 1 into 3 groups with different adverse event rates (group 1, 3.0%; group 2, 4.1%; and group 3, 9.2%, P < 0.001). A new scoring system (R-CHA2 DS2 -VASc score) derived by assigning one more point for eGFR ≤ 60 mL/min per 1.73 m(2) to the CHA2 DS2 -VASc score could improve its predictive accuracy (area under the receiver operating curve, 0.70 vs. 0.66, P < 0.001). CONCLUSIONS: Renal dysfunction is a significant risk factor of future adverse events in ACS patients and may improve the prognostic impact of the CHA2 DS2 -VASc score.

Renal dysfunction and the risk of postoperative atrial fibrillation after cardiac surgery: role beyond the CHA2DS2-VASc score.

AIMS: To investigate whether renal dysfunction is a useful predictor of postoperative atrial fibrillation (POAF) after cardiac surgery. We also aimed to determine whether the addition of renal dysfunction into the scoring system could improve diagnostic accuracy of the CHA2DS2-VASc score to predict POAF. METHODS AND RESULTS: The study prospectively enrolled 350 consecutive patients who underwent cardiac surgery. Echocardiography was performed before cardiac surgery. Renal dysfunction was defined as estimated glomerular filtration rate < 60 mL min(-1) 1.73 m(-2). All patients were monitored with continuous electrocardiographic telemetry for the occurrence of POAF until the day of hospital dismissal. Postoperative atrial fibrillation occurred in 103 of 350 patients (29%). Patients with POAF was associated with longer intensive care unit stay compared with those without POAF (3.7 ± 2.2 vs. 3.1 ± 1.4 days, P = 0.002). Both the CHA2DS2-VASc score and renal dysfunction were independent predictors of POAF in multivariate analysis. Renal dysfunction can further stratify patients with a CHA2DS2-VASc score of 0 or 1 into two groups with different POAF rates (3.1% vs. 68.8%, P < 0.001). A new scoring system (R-CHA2DS2-VASc score) derived by assigning an additional point representing renal dysfunction to the CHA2DS2-VASc score could improve its predictive accuracy. The area under the receiver operating characteristic curve increased from 0.68 to 0.71 (P < 0.001). Furthermore, the rate of left ventricular diastolic dysfunction also increased with increasing renal dysfunction. CONCLUSION: Renal dysfunction, associated with left ventricular diastolic dysfunction, was a significant risk factor for POAF after cardiac surgery and may improve the diagnostic accuracy of the CHA2DS2-VASc score.

Gender and Age Differences in Short- and Long-Term Outcomes Following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction.

BACKGROUND: Studies have reported that women with ST elevation myocardial infarction (STEMI) have worse short- and long-term outcomes than men. It has not yet been confirmed whether these differences reflect differences in age between men and women. METHODS: We retrospectively enrolled 1035 consecutive STEMI patients treated with primary percutaneous coronary intervention (PCI). Baseline clinical characteristics, coronary anatomy, and outcome were compared between young (< 65 years old) and older patients (≥ 65 years old) of both sexes. RESULTS: Younger women presented with a lower incidence of typical angina (83% vs. 93%, p = 0.03), single-vessel disease (21% vs. 35%, p = 0.03), and total occlusion of infarct-related artery (65% vs. 83%, p = 0.001) than younger men, with no gender difference noted in the older group. Younger women in the study had a higher incidence of reinfarction, heart failure requiring admission, or mortality (23% vs. 6%, p < 0.001) during follow-up, compared with younger men, with no gender difference in the older group. Using the Kaplan-Meier analysis, younger women had lower rates of event-free survival (p < 0.001 by log-rank test) than younger men, with no gender difference in the older group. In multivariate analysis, age could predict long-term outcome in men (Hazard ratio 4.43, 95% confidence interval: 2.89-6.78, p < 0.001) but not in women. CONCLUSIONS: In STEMI patients receiving primary PCI, sex-related long-term outcome differences were age-dependent, with younger women likely to have a worse long-term outcome when compared with younger men. KEY WORDS: Coronary heart disease; Gender; Myocardial infarction.

Small-conductance calcium-activated potassium channel and recurrent ventricular fibrillation in failing rabbit ventricles.

RATIONALE: Fibrillation/defibrillation episodes in failing ventricles may be followed by action potential duration (APD) shortening and recurrent spontaneous ventricular fibrillation (SVF). OBJECTIVE: We hypothesized that activation of apamin-sensitive small-conductance Ca(2+)-activated K(+) (SK) channels is responsible for the postshock APD shortening in failing ventricles. METHODS AND RESULTS: A rabbit model of tachycardia-induced heart failure was used. Simultaneous optical mapping of intracellular Ca(2+) and membrane potential (V(m)) was performed in failing and nonfailing ventricles. Three failing ventricles developed SVF (SVF group); 9 did not (no-SVF group). None of the 10 nonfailing ventricles developed SVF. Increased pacing rate and duration augmented the magnitude of APD shortening. Apamin (1 µmol/L) eliminated recurrent SVF and increased postshock APD(80) in the SVF group from 126±5 to 153±4 ms (P<0.05) and from 147±2 to 162±3 ms (P<0.05) in the no-SVF group but did not change APD(80) in nonfailing group. Whole cell patch-clamp studies at 36°C showed that the apamin-sensitive K(+) current (I(KAS)) density was significantly larger in the failing than in the normal ventricular epicardial myocytes, and epicardial I(KAS) density was significantly higher than midmyocardial and endocardial myocytes. Steady-state Ca(2+) response of I(KAS) was leftward-shifted in the failing cells compared with the normal control cells, indicating increased Ca(2+) sensitivity of I(KAS) in failing ventricles. The K(d) was 232±5 nmol/L for failing myocytes and 553±78 nmol/L for normal myocytes (P=0.002). CONCLUSIONS: Heart failure heterogeneously increases the sensitivity of I(KAS) to intracellular Ca(2+), leading to upregulation of I(KAS), postshock APD shortening, and recurrent SVF.

Association between renal function, diastolic dysfunction, and postoperative atrial fibrillation following cardiac surgery.

BACKGROUND: Renal dysfunction is associated with a higher rate of atrial fibrillation in clinical practice. This study investigated the associations between renal function, left ventricular (LV) diastolic dysfunction, and postoperative atrial fibrillation (POAF). METHODS AND RESULTS: A total of 265 consecutive patients who underwent cardiac surgery were prospectively enrolled in the study. Echocardiography was performed before cardiac surgery. The patients were divided into 3 groups based on estimated glomerular filtration rate (eGFR) (group 1, ≥90ml·min(-1)·1.73m(-2); group 2, 60-90ml·min(-1)·1.73m(-2); and group 3, <60ml·min(-1)·1.73m(-2)). POAF occurred in 83 of 265 patients (31.3%). The rate of new-onset POAF increased from 15.2% (12/79) in group 1 to 27.8% (27/97) in group 2 and 49.4% (44/89) in group 3 (P<0.001). Further, with increasing renal dysfunction from groups 1 to 3, the rate of LV diastolic dysfunction - defined as E/e' >15 - also increased (group 1, 19.0%; group 2, 38.1%; and group 3, 48.3%; P<0.001). Absolute eGFR was significantly correlated with E/e' ratio (r=-0.39, P<0.001). Renal function remained as the independent predictor of POAF on multivariate analysis (odds ratio, 1.90; 95% confidence interval: 1.26-2.87; P=0.002). CONCLUSIONS: In patients undergoing cardiac surgery, decreased eGFR was associated with an increased rate of LV diastolic dysfunction with a subsequent increase in the rate of POAF.

Improvement in door-to-balloon (D2B) time in acute ST-elevation myocardial infarction through the D2B alliance--experience of 15 primary percutaneous coronary intervention centers in Taiwan.

BACKGROUND: Currently, the door-to-balloon (D2B) times observed in clinical practice in Taiwan are different from those recommended by evidence-based guidelines. D2B Alliance, a countrywide initiative for quality supported by the Taiwan Joint Commission on Hospital Accreditation, sought to achieve the goal of administering treatment to 75% of patients with ST-elevation myocardial infarction (STEMI) within 90min of hospital presentation. METHODS AND RESULTS: The current study was designed to be prospective, national, and multicenter. We conducted a longitudinal study of the D2B times recorded in 15 primary percutaneous coronary intervention centers and examined the changes caused by implementing the D2B Alliance strategies. A total of 1,726 patients were enrolled in the D2B Alliance and implementation of the D2B Alliance strategies resulted in a significant decrease in the average D2B times (128.8 ± 42.9 min vs. 83.2 ± 16.2 min; P<0.001) from those at baseline. By the end of the year-long study, the percentage of patients treated under 90 min had increased from 46.2% to 80.1% in the hospitals enrolled in the D2B Alliance. CONCLUSIONS: Over the 1 year, hospitals enrolled in the D2B Alliance achieved the goal of reducing the D2B times of 75% of STEMI patients to less than 90 min.