Evaluation of pulse wave analysis to assess coronary artery disease

Conventional risk factors for cardiovascular disease, such as age, gender, hyperlipidaemia and hypertension are useful clinical markers of coronary artery disease (CAD) in asymptomatic patients or those without a prior history of atherosclerosis. In patients referred for a cardiology opinion, modification of risk factors by lifestyle changes and cardiac medications as well as confounding co-morbidities limit the value of these markers. Patients are often referred for diagnostic coronary angiography to determine the presence and severity of CAD, stratify the risk of future events and determine appropriate management. Despite the use of a variety of tests to best identify those requiring angiography, up to half of all patients referred do not have significant disease. Pulse wave analysis (PWA) is a novel method to derive indices of central (aortic) blood pressure and arterial stiffness. Pressure waveforms are obtained non-invasively from the radial artery using a simple tonometry method and have been shown to correlate with clinical outcomes and cardiovascular events in selected populations. This thesis will explore, for the first time, the clinical potential for PWA as a non-invasive marker of CAD in an unselected contemporary cohort of patients referred for elective coronary angiography. The main hypotheses tested are first that PWA is a suitable tool for clinical use, including those with cardiac and non-cardiac co-morbidities and second that abnormalities of PWA are independent predictors of the presence and severity of CAD. Data have been derived from a prospective, protocol-driven, multi-centre cohort of 550 patients recruited from 2006-8. Results suggest that PWA has a useful clinical role in stratifying the risk of coronary disease. PWA variables were independent of conventional blood pressure measurement and superior to baseline risk factors, biomarkers and other non-invasive tests

Cardiac imaging to assess left ventricular systolic function in atrial fibrillation

The validity and reproducibility of systolic function assessment in patients with atrial fibrillation (AF) using cardiac magnetic resonance, echocardiography, nuclear imaging and computed tomography is unknown. A prospectively-registered systematic review was performed, including 24 published studies with patients in AF at the time of imaging and reporting validity or reproducibility data on left ventricular systolic parameters (PROSPERO: CRD42018091674). Data extraction and risk of bias were performed by 2 investigators independently and synthesized qualitatively. In 3 cardiac magnetic resonance studies (40 AF patients), left ventricular ejection fraction and stroke volume measurements correlated highly with catheter angiography (r ≥0.85), and intra- and/or interobserver variability were low. From 3 nuclear studies (171 AF patients), there were no external validation assessments but intra and/or interobserver and intersession variability were low. In 18 echocardiography studies (2,566 AF patients), 2 studies showed high external validity of global longitudinal strain and tissue Doppler s’ with angiography-derived dP/dt (r ≥0.88). Global longitudinal strain and myocardial performance index were both associated with adverse cardiovascular events. Reproducibility of echocardiography was better when selecting an index-beat (where 2 preceding R-to-R intervals are similar) compared to averaging of consecutive beats. There were no studies relating to computed tomography. Most studies were small and biased by selection of patients with good quality images, limiting clinical extrapolation of results. The validity of systolic function measurements in patients with AF remains unclear due to the paucity of good-quality data

Atrial fibrillation in heart failure:What should we do?

Heart failure (HF) and atrial fibrillation (AF) are two conditions that are likely to dominate the next 50 years of cardiovascular (CV) care. Both are increasingly prevalent and associated with high morbidity, mortality, and healthcare cost. They are closely inter-related with similar risk factors and shared pathophysiology. Patients with concomitant HF and AF suffer from even worse symptoms and poorer prognosis, yet evidence-based evaluation and management of this group of patients is lacking. In this review, we evaluate the common mechanisms for the development of AF in HF patients and vice versa, focusing on the evidence for potential treatment strategies. Recent data have suggested that these patients may respond differently than those with HF or AF alone. These results highlight the clear clinical need to identify and treat according to best evidence, in order to prevent adverse outcomes and reduce the huge burden that HF and AF are expected to have on global healthcare systems in the future. We propose an easy-to-use clinical mnemonic to aid the initial management of newly discovered concomitant HF and AF, the CAN-TREAT HFrEF + AF algorithm (Cardioversion if compromised; Anticoagulation unless contraindication; Normalize fluid balance; Target initial heart rate <110 b.p.m.; Renin–angiotensin–aldosterone modification; Early consideration of rhythm control; Advanced HF therapies; Treatment of other CV disease)