Optimal surgeon and hospital volume thresholds to reduce mortality and length of stay for CABG.

OBJECTIVE: We used nationwide population-based data to identify optimal hospital and surgeon volume thresholds and to discover the effects of these volume thresholds on operative mortality and length of stay (LOS) for coronary artery bypass surgery (CABG). DESIGN: Retrospective cohort study. SETTING: General acute care hospitals throughout Taiwan. PARTICIPANTS: A total of 12,892 CABG patients admitted between 2011 and 2015 were extracted from Taiwan National Health Insurance claims data. MAIN OUTCOME MEASURES: Operative mortality and LOS. Restricted cubic splines were applied to discover the optimal hospital and surgeon volume thresholds needed to reduce operative mortality. Generalized estimating equation regression modeling, Cox proportional-hazards modeling and instrumental variables analysis were employed to examine the effects of hospital and surgeon volume thresholds on the operative mortality and LOS. RESULTS: The volume thresholds for hospitals and surgeons were 55 cases and 5 cases per year, respectively. Patients who underwent CABG from hospitals that did not reach the volume threshold had higher operative mortality than those who received CABG from hospitals that did reach the volume threshold. Patients who underwent CABG with surgeons who did not reach the volume threshold had higher operative mortality and LOS than those who underwent CABG with surgeons who did reach the volume threshold. CONCLUSIONS: This is the first study to identify the optimal hospital and surgeon volume thresholds for reducing operative mortality and LOS. This supports policies regionalizing CABG at high-volume hospitals. Identifying volume thresholds could help patients, providers, and policymakers provide optimal care.

Artificial Intelligence Aids Cardiac Image Quality Assessment for Improving Precision in Strain Measurements.

OBJECTIVES: The aim of this study was to develop an artificial intelligence tool to assess echocardiographic image quality objectively. BACKGROUND: Left ventricular global longitudinal strain (LVGLS) has recently been used to monitor cancer therapeutics-related cardiac dysfunction (CTRCD) but image quality limits its reliability. METHODS: A DenseNet-121 convolutional neural network was developed for view identification from an athlete's echocardiographic dataset. To prove the concept that classification confidence (CC) can serve as a quality marker, values of longitudinal strain derived from feature tracking of cardiac magnetic resonance (CMR) imaging and strain analysis of echocardiography were compared. The CC was then applied to patients with breast cancer free from CTRCD to investigate the effects of image quality on the reliability of strain analysis. RESULTS: CC of the apical 4-chamber view (A4C) was significantly correlated with the endocardial border delineation index. CC of A4C >900 significantly predicted a <15% relative difference in longitudinal strain between CMR feature tracking and automated echocardiographic analysis. Echocardiographic studies (n =752) of 102 patients with breast cancer without CTRCD were investigated. The strain analysis showed higher parallel forms, inter-rater, and test-retest reliabilities in patients with CC of A4C >900. During sequential comparisons of automated LVGLS in individual patients, those with CC of A4C >900 had a lower false positive detection rate of CTRCD. CONCLUSIONS: CC of A4C was associated with the reliability of automated LVGLS and could also potentially be used as a filter to select comparable images from sequential echocardiographic studies in individual patients and reduce the false positive detection rate of CTRCD.

Validation and Disease Risk Assessment of Previously Reported Genome-Wide Genetic Variants Associated With Brugada Syndrome: SADS-TW BrS Registry.

BACKGROUND: Brugada syndrome (BrS) is an oligogenic arrhythmic disease with increased risk of sudden cardiac arrest. Several BrS or ECG traits-related single-nucleotide polymorphisms (SNPs) were identified through previous genome-wide association studies in white patients. We aimed to validate these SNPs in BrS patients in the Taiwanese population, assessing the cumulative effect of risk alleles and the BrS-polygenic risk score in predicting cardiac events. METHODS: We genotyped 190 unrelated BrS patients using the TWB Array, and Taiwan Biobank was used as controls. SNPs not included in the array were imputed by IMPUTE2. Cox proportional hazards model was used to evaluate the associations between each particular SNP, the collective BrS-polygenic risk score, and clinical outcomes. RESULTS: Of the 88 previously reported SNPs, 22 were validated in Taiwanese BrS patients (P<0.05). Of the 22 SNPs, 2 (rs10428132 and rs9388451) were linked with susceptibility to BrS, 10 were SNPs previously reaching genome-wide significance, and 10 were SNPs associated with ECG traits. For the 3 most commonly reported SNPs, disease risk increased consistently with the number of risk alleles (odds ratio, 3.54; Ptrend=1.38×10-9 for 5 risk alleles versus 1). Similar patterns were observed in both SCN5A mutation+ (odds ratio, 3.66; Ptrend=0.049) and SCN5A mutation- (odds ratio, 3.75; Ptrend=8.54×10-9) subgroups. Furthermore, BrS patients without SCN5A mutations had more risk alleles than BrS patients with SCN5A mutations regardless of the range of polygenic risk scores. Three SNPs (rs4687718, rs7784776, and rs2968863) showed significant associations with the composite outcome (sudden cardiac arrest plus syncope, hazard ratio, 2.13, 1.48, and 0.41; P=0.02, 0.006, and 0.008, respectively). CONCLUSIONS: Our findings suggested that some SNPs associated with BrS or ECG traits exist across multiple populations. The cumulative risk of the BrS-related SNPs is similar to that in white BrS patients, but it appears to correlate with the absence of SCN5A mutations.

Cost-effectiveness of amlodipine compared with valsartan in preventing stroke and myocardial infarction among hypertensive patients in Taiwan.

Hypertension is a major risk factor for strokes and myocardial infarction (MI). Given its effectiveness and safety profile, the calcium channel blocker amlodipine is among the most frequently prescribed antihypertensive drugs. This analysis was conducted to determine the costs and quality-adjusted life years (QALYs) associated with the use of amlodipine and valsartan, an angiotensin II receptor blocker, in preventing stroke and MI in Taiwanese hypertensive patients. A state transition (Markov) model was developed to compare the 5-year costs and QALYs for amlodipine and valsartan. Effectiveness data were based on the NAGOYA HEART Study, local studies, and a published meta-analysis. Utility data and costs of MI and stroke were retrieved from the published literature. Medical costs were based on the literature and inflated to 2011 prices; drug costs were based on National Health Insurance prices in 2014. A 3% discount rate was used for costs and QALYs and a third-party payer perspective adopted. One-way sensitivity and scenario analyses were conducted. Compared with valsartan, amlodipine was associated with cost savings of New Taiwan Dollars (NTD) 2,251 per patient per year: costs were NTD 4,296 and NTD 6,547 per patient per year for amlodipine and valsartan users, respectively. Fewer cardiovascular events were reported in patients receiving amlodipine versus valsartan (342 vs 413 per 10,000 patients over 5 years, respectively). Amlodipine had a net gain of 58 QALYs versus valsartan per 10,000 patients over 5 years. Sensitivity analyses showed that the discount rate and cohort age had a larger effect on total cost and cost difference than on QALYs. However, amlodipine results were more favorable than valsartan irrespective of discount rate or cohort age. When administered to Taiwanese patients for hypertension control, amlodipine was associated with lower cost and more QALYs compared with valsartan due to a lower risk of stroke and MI events.

Anti-anxiety drugs use and cardiovascular outcomes in patients with myocardial infarction: a national wide assessment.

OBJECTIVE: Anti-anxiety medication in patients with anxiety may lessen the stress and thereby lower their risk for myocardial infarction (MI). The aim of current study is to examine an association between the use of anti-anxiety medication and long-term mortality risk in patients following MI. METHODS: A universal national health insurance (NHI) program has been implemented in Taiwan since 1995. We used system sampling database from 1997 to 2008 with a total of 1,000,000 subjects. We included subjects with first episode of MI and were above 30 years old. Sudden death, cardiovascular mortality, and heart failure hospitalization were assessed in all included subjects. Anti-anxiety as well as other medications and risk factors were obtained. Cox regression analysis was used to evaluate the adjusted hazard ratio (HR) for all patients and subgroups. RESULTS: The adjusted HRs of sudden death were significantly associated with increased benzodiazepam (BZD) dosage (HRs = 0.639, 1.003, 1.957 from Q2 to Q4 vs. Q1, p = .019 for trend) during approximately 4.8 years. For cardiac mortality and heart failure hospitalization, there was a J-curve dose-response relationship. The HRs for cardiac mortality were 0.255 (p < .001) and 0.385 (p < .001) for Q2 and Q3 vs. Q1, respectively. For patients receiving higher doses of daily BZDs (>5 mg), protective effects for cardiac mortality and heart failure hospitalization decreased and a J-curve dose-response relationship was seen. CONCLUSION: Anti-anxiety medications are independent associated with a decreased risk of cardiac mortality and heart failure hospitalization in patients after a new MI.

Using paper chart based clinical reminders to improve guideline adherence to lipid management.

RATIONALE, AIMS AND OBJECTIVES: The objective of this study was to apply a paper-based clinical reminder to improve the adherence to lipid guidelines. METHODS: Patients with coronary heart disease (CHD) without lipid-lowering therapy (LLT) were recruited, and medical records were reviewed. Eligible subjects were randomized; a clinical reminder stating current standards and local insurance policy was stamped on the paper chart in the study group but not in the control. The primary outcome was new LLT subscription in the 6-month follow-up period, and the secondary end point was the composite result of LLT or lipid profile check-up. RESULTS: Ninety-two patients were assigned to the study group and 102 to the control group. The primary outcome showed no difference at the end of 6 months (OR: 1.70, P = 0.248, 95% CI: 0.69-4.19). The secondary end point was significantly higher in the reminder group (OR: 2.81, P = 0.001, 95% CI: 1.57-5.04). CONCLUSION: A paper chart based clinical reminder providing update clinical recommendations could modify the doctor's behaviour and improve the attention to lipid levels. However, its effect cannot be transformed into an increase in LLT or a decrease in low-density lipoprotein level owing to local policy constraint.