Category: Cardiology

Hot Topics: Stroke Increases Risk of Heart Complications

jackiewe Cardiology, Hot Topics in Research, Neurology

First-Ever Ischemic Stroke and Incident Major Adverse Cardiovascular Events in 93,627 Older Women and Men

Sposato Luciano A, Melody L, Britney A, Shariff Salimah Z, Gustavo S. First-ever ischemic stroke and incident major adverse cardiovascular events in 93 627 older women and men. Stroke. https://doi.org/10.1161/STROKEAHA.119.028066.

Background and Purpose

Stroke risk is sex-specific, but little is known about sex differences of poststroke major adverse cardiovascular events (MACEs). Stroke-related brain damage causes autonomic dysfunction and inflammation, sometimes resulting in cardiac complications. Sex-specific cardiovascular susceptibility to stroke without the confounding effect of preexisting heart disease constitutes an unexplored field because previous studies focusing on sex differences in poststroke MACE have not excluded patients with known cardiovascular comorbidities. We therefore investigated sex-specific risks of incident MACE in a heart disease-free population-based cohort of patients with first-ever ischemic stroke and propensity-matched individuals without stroke.

Methods

We included Ontario residents ≥66 years, without known cardiovascular comorbidities, with first-ever ischemic stroke between 2002 and 2012 and propensity-matched individuals without stroke. We investigated the 1-year risk of incident MACE (acute coronary syndrome, myocardial infarction, incident coronary artery disease, coronary revascularization procedures, incident heart failure, or cardiovascular death) separately for females and males. For estimating cause-specific adjusted hazard ratios, we adjusted Cox models for variables with weighted standardized differences >0.10 or those known to influence MACE risk.

Results

We included 93 627 subjects without known cardiovascular comorbidities; 21 931 with first-ever ischemic stroke and 71 696 propensity-matched subjects without stroke. Groups were well-balanced on propensity-matching variables. There were 53 476 women (12 421 with and 41 055 without ischemic stroke) and 40 151 men (9510 with and 30 641 without ischemic stroke). First-ever ischemic stroke was associated with increased risk of incident MACE in both sexes. The risk was time-dependent, highest within 30 days (women: adjusted hazard ratio, 25.1 [95% CI, 19.3–32.6]; men: aHR, 23.4 [95% CI, 17.2–31.9]) and decreasing but remaining significant between 31 and 90 days (women: aHR, 4.8 [95% CI, 3.8–6.0]; men: aHR, 4.2 [95% CI, 3.3–5.4]), and 91 to 365 days (aHR, 2.1 [95% CI, 1.8–2.3]; men: aHR, 2.0 [95% CI, 1.7–2.3]).

Conclusions

In this large population-based study, ischemic stroke was independently associated with increased risk of incident MACE in both sexes.

Hot Topics: New Factors Could Reverse Arterial Plaque Buildup

jackiewe Cardiology, Hot Topics in Research

Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis

Chen, P., Qin, L., Li, G., Wang, Z., Dahlman, J. E., Malagon-Lopez, J., . . . Simons, M. (2019). Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis. Nature Metabolism, http://doi.org/10.1038/s42255-019-0102-3

Atherosclerosis is a progressive vascular disease triggered by interplay between abnormal shear stress and endothelial lipid retention. A combination of these and, potentially, other factors leads to a chronic inflammatory response in the vessel wall, which is thought to be responsible for disease progression characterized by a buildup of atherosclerotic plaques. Yet molecular events responsible for maintenance of plaque inflammation and plaque growth have not been fully defined. Here we show that endothelial transforming growh factor β (TGF-β) signalling is one of the primary drivers of atherosclerosis-associated vascular inflammation. Inhibition of endothelial TGF-β signalling in hyperlipidemic mice reduces vessel wall inflammation and vascular permeability and leads to arrest of disease progression and regression of established lesions. These proinflammatory effects of endothelial TGF-β signalling are in stark contrast with its effects in other cell types and identify it as an important driver of atherosclerotic plaque growth and show the potential of cell-type-specific therapeutic intervention aimed at control of this disease.

Hot Topics: Algorithm Predicts Irregular Heartbeats

jackiewe Cardiology, Hot Topics in Research

A New Prediction Model for Ventricular Arrhythmias in Arrhythmogenic Right Ventricular Cardiomyopathy

Bhonsale A, Murray B, Tichnell C, et al. A new prediction model for ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy. . 2019. https://doi.org/10.1093/eurheartj/ehz103.

Aims: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC) is characterized by ventricular arrhythmias (VAs) and sudden cardiac death (SCD). We aimed to develop a model for individualized prediction of incident VA/SCD in ARVC patients.

Methods and Results: Five hundred and twenty-eight patients with a definite diagnosis and no history of sustained VAs/SCD at baseline, aged 38.2 ± 15.5 years, 44.7% male, were enrolled from five registries in North America and Europe. Over 4.83 (interquartile range 2.44–9.33) years of follow-up, 146 (27.7%) experienced sustained VA, defined as SCD, aborted SCD, sustained ventricular tachycardia, or appropriate implantable cardioverter-defibrillator (ICD) therapy. A prediction model estimating annual VA risk was developed using Cox regression with internal validation. Eight potential predictors were pre-specified: age, sex, cardiac syncope in the prior 6 months, non-sustained ventricular tachycardia, number of premature ventricular complexes in 24 h, number of leads with T-wave inversion, and right and left ventricular ejection fractions (LVEFs). All except LVEF were retained in the final model. The model accurately distinguished patients with and without events, with an optimism-corrected C-index of 0.77 [95% confidence interval (CI) 0.73–0.81] and minimal over-optimism [calibration slope of 0.93 (95% CI 0.92–0.95)]. By decision curve analysis, the clinical benefit of the model was superior to a current consensus-based ICD placement algorithm with a 20.6% reduction of ICD placements with the same proportion of protected patients (P < 0.001).

Conclusion: Using the largest cohort of patients with ARVC and no prior VA, a prediction model using readily available clinical parameters was devised to estimate VA risk and guide decisions regarding primary prevention ICDs (www.arvcrisk.com).

Hot Topics: Botox May Help Aftermath of Cardiac Surgery

jackiewe Cardiology, Hot Topics in Research, Surgery

Long-term suppression of atrial fibrillation by botulinum toxin injection into epicardial fat pads in patients undergoing cardiac surgery: Three-year follow-up of a randomized study
Romanov A, Pokushalov E, Ponomarev D, et al. Long-term suppression of atrial fibrillation by botulinum toxin injection into epicardial fat pads in patients undergoing cardiac surgery: Three-year follow-up of a randomized study. Heart Rhythm. 2018. http://dx.doi.org/10.1016/j.hrthm.2018.08.019
Background
Botulinum toxin (BTX) injections into epicardial fat pads in patients undergoing coronary artery bypass grafting (CABG) has resulted in suppression of atrial fibrillation (AF) during the early postoperative period through 1-year of follow-up in a pilot program.
Objective
The purpose of this study was to report 3-year AF patterns by the use of implantable cardiac monitors (ICMs).
Methods
Sixty patients with a history of paroxysmal AF and indications for CABG were randomized 1:1 to either BTX or placebo injections into 4 posterior epicardial fat pads. All patients received an ICM with regular follow-up for 3 years after surgery. The primary end point of the extended follow-up period was incidence of any atrial tachyarrhythmia after 30 days of procedure until 36 months on no antiarrhythmic drugs. The secondary end points included clinical events and AF burden.
Results
At the end of 36 months, the incidence of any atrial tachyarrhythmia was 23.3% in the BTX group vs 50% in the placebo group (hazard ratio 0.36; 95% confidence interval 0.14–0.88; P = .02). AF burden at 12, 24, and 36 months was significantly lower in the BTX group than in the placebo group: 0.22% vs 1.88% ( P = .003), 1.6% vs 9.5% ( P < .001), and 1.3% vs 6.9% ( P = .007), respectively. In the BTX group, 2 patients (7%) were hospitalized during follow-up compared with 10 (33%) in the placebo group ( P = .02).
Conclusion
Injection of BTX into epicardial fat pads in patients undergoing CABG resulted in a sustained and substantial reduction in atrial tachyarrhythmia incidence and burden during 3-year follow-up, accompanied by reduction in hospitalizations.

Hot Topics: Assessment Identifies Patients At Risk for Cardiac-Induced PTSD

jackiewe Cardiology, Hot Topics in Research, Psychology and Psychiatry

Development and Validation of a Measure to Assess Patients’ Threat Perceptions in the Emergency Department
Cornelius T, Agarwal S, Garcia O, Chaplin W, Edmondson D, Chang BP. Development and validation of a measure to assess patients’ threat perceptions in the emergency department. Acad Emerg Med. 2018;0. https://doi.org/10.1111/acem.13513.

Objective

Threat perceptions in the Emergency Department (ED) (e.g., patients’ subjective feelings of helplessness or lack of control) during evaluation for an acute coronary syndrome (ACS) are associated with the development of posttraumatic stress disorder (PTSD), and PTSD has been associated with medication nonadherence, cardiac event recurrence, and mortality. This study reports the development and validation of a 7‐item measure of ED Threat Perceptions in English‐ and Spanish‐speaking patients evaluated for ACS.

Methods

Participants were drawn from an observational cohort study of 1,000 patients evaluated for ACS between 2013‐2016 in a large, New York City hospital. Participants reported on threat perceptions in the ED and during inpatient stay (using 12 items previously identified as predictive of PTSD) and reported on cardiac‐induced PTSD one month post‐discharge. Exploratory and confirmatory factor analyses were used to establish the factor structure and test measurement invariance. Validity and reliability were examined, as was the association of ED Threat Perceptions with cardiac‐induced PTSD.

Results

Factor analyses identified a 7‐item measure of ED Threat Perceptions (e.g., “I feel helpless,” “I am worried that I am going to die”) for both English‐ and Spanish‐speaking patients. ED Threat Perceptions demonstrated convergent validity, correlating with ED stress and ED crowdedness (rs = .29, .14), good internal consistency (α = .82), and stability (r = .61). Threat Perceptions were associated with cardiac‐induced acute stress at inpatient and PTSD symptoms at one month (rs = .43, .39).

Conclusions

This brief tool assessing ED Threat Perceptions has clinical utility for providers to identify patients at risk for developing cardiac‐induced PTSD and is critical to inform research on whether threat may be modified in‐ED to reduce PTSD incidence.

Hot Topics: AI Model Better Predicts Heart Disease Deaths

jackiewe Cardiology, Hot Topics in Research

Machine learning models in electronic health records can outperform conventional survival models for predicting patient mortality in coronary artery disease
Steele AJ, Denaxas SC, Shah AD, Hemingway H, Luscombe NM. Machine learning models in electronic health records can outperform conventional survival models for predicting patient mortality in coronary artery disease. PLOS ONE. 2018;13(8):e0202344. https://doi.org/10.1371/journal.pone.0202344.
Prognostic modelling is important in clinical practice and epidemiology for patient management and research. Electronic health records (EHR) provide large quantities of data for such models, but conventional epidemiological approaches require significant researcher time to implement. Expert selection of variables, fine-tuning of variable transformations and interactions, and imputing missing values are time-consuming and could bias subsequent analysis, particularly given that missingness in EHR is both high, and may carry meaning. Using a cohort of 80,000 patients from the CALIBER programme, we compared traditional modelling and machine-learning approaches in EHR. First, we used Cox models and random survival forests with and without imputation on 27 expert-selected, preprocessed variables to predict all-cause mortality. We then used Cox models, random forests and elastic net regression on an extended dataset with 586 variables to build prognostic models and identify novel prognostic factors without prior expert input. We observed that data-driven models used on an extended dataset can outperform conventional models for prognosis, without data preprocessing or imputing missing values. An elastic net Cox regression based with 586 unimputed variables with continuous values discretised achieved a C-index of 0.801 (bootstrapped 95% CI 0.799 to 0.802), compared to 0.793 (0.791 to 0.794) for a traditional Cox model comprising 27 expert-selected variables with imputation for missing values. We also found that data-driven models allow identification of novel prognostic variables; that the absence of values for particular variables carries meaning, and can have significant implications for prognosis; and that variables often have a nonlinear association with mortality, which discretised Cox models and random forests can elucidate. This demonstrates that machine-learning approaches applied to raw EHR data can be used to build models for use in research and clinical practice, and identify novel predictive variables and their effects to inform future research.

Hot Topics: Genetic Cause of Final Blood Group System Discovered

jackiewe Blood, Cardiology, Hot Topics in Research

Disruption of a GATA1-binding motif upstream of XG/PBDX abolishes Xga expression and resolves the Xg blood group system
Möller M, Lee YQ, Vidovic K, et al. Disruption of a GATA1-binding motif upstream of XG/PBDX abolishes Xga expression and resolves the Xg blood group system. Blood. 2018. http://dx.doi.org/10.1182/blood-2018-03-842542.
The Xga blood group is differentially expressed on erythrocytes from males and females. The underlying gene, PBDX, was identified already in 1994 but the molecular background for Xga expression remains undefined. This gene, now designated XG, partly resides in the pseudoautosomal region 1 and encodes a protein of unknown function from the X chromosome. By comparing calculated Xgaallele frequencies in different populations to 2,612 genetic variants in the XG region, rs311103 showed the strongest correlation to the expected distribution. The same SNP had the most significant impact on XG transcript levels in whole blood (P=2.0×10-22). The minor allele, rs311103C, disrupts a GATA-binding motif 3.7 kb upstream of the transcription start point. This silences erythroid XG-mRNA expression and causes the Xg(a–) phenotype, a finding corroborated by SNP genotyping in 119 blood donors. Binding of GATA1 to biotinylated oligonucleotide probes with rs311103G but not rs311103C was observed by EMSA and proven by mass spectrometry. Finally, a luciferase reporter assay indicated this GATA motif to be active for rs311103G but not rs311103C in HEL cells. By using an integrated bioinformatics and molecular biology approach, we elucidated the underlying genetic basis for the last unresolved blood group system and made Xga genotyping possible.

Hot Topics: Gut Bacteria May Change Course of Atherosclerosis

jackiewe Cardiology, Hot Topics in Research

Metabolic Products of the Intestinal Microbiome and Extremes of Atherosclerosis
Bogiatzi C, Gloor G, Allen-Vercoe E, et al. Metabolic products of the intestinal microbiome and extremes of atherosclerosis. Atherosclerosis. 2018;273:91-97. doi: https://doi.org/10.1016/j.atherosclerosis.2018.04.015.
Background and aims
There is increasing awareness that the intestinal microbiome plays an important role in human health. We investigated its role in the burden of carotid atherosclerosis, measured by ultrasound as total plaque area.
Methods
Multiple regression with traditional risk factors was used to identify three phenotypes among 316/3056 patients attending vascular prevention clinics. Residual score (RES; i.e. the distance off the regression line, similar to standard deviation) was used to identify the 5% of patients with much less plaque than predicted by their risk factors (Protected, RES <−2), the 90% with about as much plaque as predicted (Explained, RES -2 to 2), and the 5% with much more plaque than predicted (Unexplained RES >2). Metabolic products of the intestinal microbiome that accumulate in renal failure – gut-derived uremic toxins (GDUT) – were assayed in plasma by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.
Results
Plasma levels of trimethylamine n-oxide (TMAO), p-cresyl sulfate, p-cresyl glucuronide, and phenylacetylglutamine were significantly lower among patients with the Protected phenotype, and higher in those with the Unexplained phenotype, despite no significant differences in renal function or in dietary intake of nutrient precursors of GDUT. In linear multiple regression with a broad panel of risk factors, TMAO (p = 0.011) and p-cresyl sulfate (p = 0.011) were significant independent predictors of carotid plaque burden.
Conclusions
The intestinal microbiome appears to play an important role in atherosclerosis. These findings raise the possibility of novel approaches to treatment of atherosclerosis such as fecal transplantation and probiotics.

Hot Topics: New Guidelines Lower Threshold for High Blood Pressure

jackiewe Cardiology, Hot Topics in Research
Potential U.S. Population Impact of the 2017 American College of Cardiology/American Heart Association High Blood Pressure Guideline
Muntner, P., Carey, R. M., Gidding, S., Jones, D. W., Taler, S. J., Wright, J. T., & Whelton, P. K. (2017). Potential U.S. population impact of the 2017 American Ccollege of Cardiology/American Heart Association high blood pressure guideline. Journal of the American College of Cardiology. doi: 10.1016/j.jacc.2017.10.073

Background The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults provides recommendations for the definition of hypertension, systolic and diastolic blood pressure (BP) thresholds for initiation of antihypertensive medication and BP target goals.

Objective Determine the prevalence of hypertension, implications of recommendations for antihypertensive medication and prevalence of BP above the treatment goal among US adults using criteria from the 2017 ACC/AHA and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC7) guidelines.

Methods We analyzed data from the 2011-2014 National Health and Nutrition Examination Survey (N=9,623). NHANES participants completed study interviews and an examination. For each participant, blood pressure was measured three times following a standardized protocol and averaged. Results were weighted to produce US population estimates.

Results According to the 2017 ACC/AHA and JNC7 guidelines, the overall crude prevalence of hypertension among US adults was 45.6% (95% confidence interval [CI] 43.6%,47.6%) and 31.9% (95%CI 30.1%, 33.7%), respectively, and antihypertensive medication was recommended for 36.2% (95%CI 34.2%, 38.2%) and 34.3% (32.5%, 36.2%) of US adults, respectively. Compared to US adults recommended antihypertensive medication by JNC7, those recommended treatment by the 2017 ACC/AHA guideline but not JNC7 had higher CVD risk. Non-pharmacological intervention is advised for the 9.4% of US adults with hypertension according to the 2017 ACC/AHA guideline who are not recommended antihypertensive medication. Among US adults taking antihypertensive medication, 53.4% (95%CI 49.9%, 56.8%) and 39.0% (95%CI 36.4%, 41.6%) had BP above the treatment goal according to the 2017 ACC/AHA and JNC7 guidelines, respectively. Overall, 103.3 (95%CI 92.7, 114.0) million US adults had hypertension according to the 2017 ACC/AHA guideline of whom 81.9 (95%CI 73.8, 90.1) million were recommended antihypertensive medication.

Conclusion Compared with the JNC 7 guideline, the 2017 ACC/AHA guideline results in a substantial increase in the prevalence of hypertension but a small increase in the percentage of U.S. adults recommended antihypertensive medication. A substantial proportion of US adults taking antihypertensive medication is recommended more intensive BP lowering under the 2017 ACC/AHA guideline.

Hot Topics: Atrial Fibrillation May Be Commonly Undiganosed

jackiewe Cardiology, Hot Topics in Research

Incidence of Previously Undiagnosed Atrial Fibrillation Using Insertable Cardiac Monitors in a High-Risk Population: The REVEAL AF Study
Reiffel JA, Verma A, Kowey PR, al e. Incidence of previously undiagnosed atrial fibrillation using insertable cardiac monitors in a high-risk population: The reveal af study. JAMA Cardiology. 2017. http://dx.doi.org/10.1001/jamacardio.2017.3180.
Importance  In approximately 20% of atrial fibrillation (AF)–related ischemic strokes, stroke is the first clinical manifestation of AF. Strategies are needed to identify and therapeutically address previously undetected AF.
Objective  To quantify the incidence of AF in patients at high risk for but without previously known AF using an insertable cardiac monitor.
Design, Setting, and Participants  This prospective, single-arm, multicenter study was conducted from November 2012 to January 2017. Visits took place at 57 centers in the United States and Europe. Patients with a CHADS2 score of 3 or greater (or 2 with at least 1 additional risk factor) were enrolled. Approximately 90% had nonspecific symptoms potentially compatible with AF, such as fatigue, dyspnea, and/or palpitations.
Exposures  Patients underwent monitoring with an insertable cardiac monitor for 18 to 30 months.
Main Outcomes and Measures  The primary end point was adjudicated AF lasting 6 or more minutes and was assessed at 18 months. Other analyses included detection rates at points from 30 days to 30 months and among CHADS2 score subgroups. Median time from insertion to detection and the percentage of patients subsequently prescribed oral anticoagulation therapy was also determined.
Results  A total of 446 patients were enrolled; 233 (52.2%) were male, and the mean (SD) age was 71.5 (9.9) years. A total of 385 patients (86.3%) received an insertable cardiac monitor, met the primary analysis cohort definition, and were observed for a mean (SD) period of 22.5 (7.7) months. The detection rate of AF lasting 6 or more minutes at 18 months was 29.3%. Detection rates at 30 days and 6, 12, 24, and 30 months were 6.2%, 20.4%, 27.1%, 33.6%, and 40.0%, respectively. At 18 months, AF incidence was similar among patients with CHADS2 scores of 2 (24.7%; 95% CI, 17.3-31.4), 3 (32.7%; 95% CI, 23.8-40.7), and 4 or greater (31.7%; 95% CI, 22.0-40.3) (P = .23). Median (interquartile) time from device insertion to first AF episode detection was 123 (41-330) days. Of patients meeting the primary end point, 13 (10.2%) had 1 or more episodes lasting 24 hours or longer, and oral anticoagulation therapy was prescribed for 72 patients (56.3%).
Conclusions and Relevance  The incidence of previously undiagnosed AF may be substantial in patients with risk factors for AF and stroke. Atrial fibrillation would have gone undetected in most patients had monitoring been limited to 30 days. Further trials regarding the value of detecting subclinical AF and of prophylactic therapies are warranted.