Lin, Grace

Screening for hepatopulmonary syndrome (HPS) using pulse oximetry is recommended in liver transplant (LT) candidates because mortality is increased, independently of the severity of the oxygenation defect. LT exception points may be afforded to those with HPS and severe hypoxemia. We assessed the screening characteristics of pulse oximetry for HPS. The Pulmonary Vascular Complications of Liver Disease 2 study is a multicenter, prospective cohort study of adults undergoing their first LT evaluation. Patients underwent protocolized assessment of oxygen saturation by pulse oximetry (SpO2), arterial blood gas, spirometry, and contrast‐enhanced echocardiography (CE). HPS was defined as an alveolar‐arterial gradient ≥15 mm Hg (≥20 mm Hg if age >64 years), intrapulmonary vascular dilatation on CE, and absence of lung disease. The study sample included 363 patients. Of these, 75 (20.7%; 95% confidence interval [CI], 16.6%‐25.2%) met the criteria for HPS. The area under the receiver operating characteristic curve (or c‐statistic) for SpO2 in discriminating HPS was 0.59 (95% CI, 0.51‐0.66). An SpO2 <96%, recommended by practice guidelines as a threshold to require further testing, had low sensitivity (28%; 95% CI, 18%‐28%). The c‐statistic of SpO2 in discriminating HPS with a partial pressure of oxygen (PaO2) <60 mm Hg (eligible for LT exception points) was 0.76 (95% CI, 0.46‐1.00). An SpO2 cutoff of <96% had higher sensitivity for detecting HPS with PaO2 <60 mm Hg (71%; 95% CI, 38%‐100%) but was still inadequate. Conclusion: Pulse oximetry is not sufficiently sensitive to screen for HPS in LT candidates. Arterial blood gas and CE are required in LT candidates for diagnosis of HPS.

Introduction The role of cardiac implantable electronic device (CIED) therapy in patients with ATTR-wt (senile) amyloid is not very well defined. It is unknown whether there is mortality benefit or harm with the implantation of CIEDs. Methods We performed a retrospective analysis of a prospectively collected registry of patients with biopsy proven ATTR-wt amyloid with cardiac involvement. These patients were followed up at Mayo Clinic, Rochester, Minnesota between Jan 1, 1985 to Sep 30, 2015. The follow-up of these patients was done via personal communication (written or verbal) and entered into the database. During analysis these patients were subdivided on the basis of the presence or absence of a CIED, cardiac involvement or not, and all-cause mortality analysed. The implantation of a CIED was analysed as a time-dependent covariate in the survival of these patients and Kaplan-Meier (K-M) survival plots created. Comparison between groups with CIED and those without CIED was made. In addition, CIEDs were subdivided into permanent pacemakers (PPM), defibrillators (ICDs) and cardiac resynchronization devices (CRT-P/D). Mortality among the patients with each device subtype was estimated and compared to overall mortality. Results 409 patients with ATTR-wt and cardiac involvement were reviewed with CIEDs implanted in 101 (25%) patients. The median follow-up (25th, 75th centile) was 2.4 (1.1, 4.3) years. Utilisation of ICDs in this population was higher than the general community in Olmsted county. There was no association in the overall survival or evidence of harm with CIED utilisation in patients with ATTR amyloidosis and cardiac involvement. Conclusions CIEDs utilisation remains high in ATTR-wt with cardiac involvement. Due diligence is needed in selecting the optimal patient for benefit prior to the implantation of CIEDs in this cohort. Further research is required to pool multi-centre amyloid registry data and determine if there is mortality benefit.

Objectives To define the prognostic contribution of global and regional left ventricular (LV) function measurements in patients with ischaemic cardiomyopathy randomised to coronary artery bypass graft surgery (CABG) with (n=501) or without (n=499) surgical ventricular reconstruction (SVR). Methods Novel multivariable methods to analyse global and regional LV systolic function were used to better formulate prediction models for long-term mortality following CABG with or without SVR in the entire cohort of 1000 randomised SVR hypothesis patients. Key clinical variables were included in the analysis. Regional function was classified according to the discreteness of anteroapical hypokinesia and akinesia into those most likely to benefit from SVR, those least likely and those felt to have intermediate likelihood of benefit from SVR. Results The most prognostic clinical variables identified in multivariable models include creatinine, LV end-systolic volume index (ESVI), age and NYHA (New York Heart Association) class. Addition of LV ejection fraction, LV end-diastolic volume index and regional function assessment did not contribute additional power to the model. Subgroup analysis based on regional function did not identify a cohort in which SVR improved mortality. Conclusions ESVI is the single parameter of LV function most predictive of mortality in patients with LV systolic dysfunction following CABG with or without SVR in multivariable models that include all key clinical and LV systolic function parameters. Assessment of regional cardiac function does not enhance prediction of mortality nor identify a subgroup for which SVR improves mortality. These results do not support elective addition of LV reconstruction surgery in patients undergoing CABG. Trial registration number NCT00023595.

Objective Sudden cardiac arrest (SCA) is the most devastating outcome in hypertrophic cardiomyopathy (HCM). We evaluated repolarisation features on the surface electrocardiogram (ECG) to identify the potential risk factors for SCA. Methods Data was collected from 52 patients with HCM who underwent implantable cardioverter defibrillator (ICD) implantation. Leads V2 and V5 from the ECG closest to the time of ICD implant were utilised for measuring the Tpeak-Tend interval (Tpe), QTc, Tpe/QTc, T-wave duration and T-wave amplitude. The presence of the five traditional SCA-associated risk factors was assessed, as well as the HCM risk-SCD score. Results 16 (30%) patients experienced aborted cardiac arrest over 8.5±4.1 years, with 9 receiving an ICD shock and 7 receiving ATP. On univariate analysis, T-wave amplitude was associated with appropriate ICD therapy (HR per 0.1 mV 0.79, 95% CI 0.56 to 0.96, p=0.02). Aborted SCA was not associated with a greater mean QTc duration, Tpeak-Tend interval, T-wave duration, or Tpe/QT ratio. Multivariate analysis (adjusting for cardinal HCM SCA-risk factors) showed T-wave amplitude in Lead V2 was an independent predictor of risk (adjusted HR per 0.1 mV 0.74, 95% CI 0.57 to 0.97, p=0.03). Addition of T-wave amplitude in Lead V2 to the traditional risk factors resulted in significant improvement in risk stratification (C-statistic from 0.65 to 0.75) but did not improve the performance of the HCM SCD-risk score. Conclusions T-wave amplitude is a novel marker of SCA in this high risk HCM population and may provide incremental predictive value to established risk factors. Further work is needed to define the role of repolarisation abnormalities in predicting SCA in HCM.

Abstract Background While abnormal left ventricular (LV) global longitudinal strain (GLS) has been described in patients with heart failure with preserved ejection fraction (HFpEF), its prevalence and clinical significance are poorly understood. Methods and results Patients enrolled in the RELAX trial of sildenafil in HFpEF (LV ejection fraction ≥50%) in whom two-dimensional, speckle-tracking LV GLS was possible (n = 187) were analysed. The distribution of LV GLS and its associations with clinical characteristics, LV structure and function, biomarkers, exercise capacity and quality of life were assessed. Baseline median LV GLS was −14.6% (25th and 75th percentile, −17.0% and −11.9%, respectively) and abnormal (≥ − 16%) in 122/187 (65%) patients. Patients in the tertile with the best LV GLS had lower N-terminal pro-brain natriuretic peptide (NT-proBNP) [median 505 pg/mL (161, 1065) vs. 875 pg/mL (488, 1802), P = 0.008) and lower collagen IIIN-terminal propeptide (PIIINP) levels [median 6.7 µg/L (5.1, 8.1) vs. 8.1 µg/L (6.5, 10.5), P = 0.001] compared with the tertile with the worst LV GLS. There was also a modest linear relationship with LV GLS and log-transformed NT-proBNP and PIIINP (r = 0.29, P &lt; 0.001 and r = 0.19, P = 0.009, respectively). We observed no linear association of LV GLS with Minnesota Living with Heart Failure scores, 6-min walk distance, peak oxygen consumption, or expiratory minute ventilation/carbon dioxide excretion slope. Conclusions Impaired LV GLS is common among HFpEF patients, indicating the presence of covert systolic dysfunction despite normal LV ejection fraction. Impaired LV GLS was associated with biomarkers of wall stress and collagen synthesis and diastolic dysfunction but not with quality of life or exercise capacity, suggesting other processes may be more responsible for these aspects of the HFpEF syndrome.

Background— Afterload reduction is a cornerstone in the management of patients with heart failure (HF) and reduced ejection fraction. However, arterial load and the effect of HF therapies on afterload might vary between individuals. Tailoring vasoactive medicines to patients with HF based upon better understanding of arterial afterload may enable better individualization of therapy. Methods and Results— Subjects with HF and reduced ejection fraction underwent aggressive titration of vasoactive HF therapies with assessment of central aortic waveforms analyzed using pulse wave, wave separation, and arterial reservoir models. Clinical response to treatment was assessed using the 6-minute walk test distance, which increased in 25 subjects and decreased or remained unchanged in 13. Subjects with improvement on therapy displayed higher aortic pressure wave pulsatility (central pulse pressure [PP], reflected pressure wave, and reservoir pressure) at study entry compared with subjects without improvement (all P <0.05). Parameters derived by the arterial analysis methods were strongly correlated with one another and displayed similar ability to predict improvement. Aortic pressure pulsatility significantly decreased in subjects with functional improvement, whereas no change was observed in patients without functional improvement ( P for interaction <0.05). These differences in arterial load at baseline and on therapy were not apparent from conventional brachial artery cuff pressure assessments. Conclusions— Increased aortic pressure wave pulsatility and greater decrease in pulsatility on treatment are associated with functional improvement in patients with HF and reduced ejection fraction receiving aggressive vasodilator titration. These differences are not identifiable using brachial cuff pressures. Central aortic waveform analysis may enable better individualization of vasoactive therapies in chronic HF and reduced ejection fraction. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00588692.