The clinical impact of contemporary stress echocardiography in morbid obesity for the assessment of coronary artery disease

Stress CMR in patients with obesity: insights from the Stress CMR Perfusion Imaging in the United States (SPINS) registry

AIMS

Non-invasive assessment and risk stratification of coronary artery disease in patients with large body habitus is challenging. We aim to examine whether body mass index (BMI) modifies the prognostic value and diagnostic utility of stress cardiac magnetic resonance imaging (CMR) in a multicentre registry.

METHODS AND RESULTS

The SPINS Registry enrolled consecutive intermediate-risk patients who presented with a clinical indication for stress CMR in the USA between 2008 and 2013. Baseline demographic data including BMI, CMR indices, and ratings of study quality were collected. Primary outcome was defined by a composite of cardiovascular death and non-fatal myocardial infarction. Of the 2345 patients with available BMI included in the SPINS cohort, 1177 (50%) met criteria for obesity (BMI ≥ 30) with 531 (23%) at or above Class 2 obesity (BMI ≥ 35). In all BMI categories, >95% of studies were of diagnostic quality for cine, perfusion, and late gadolinium enhancement (LGE) sequences. At a median follow-up of 5.4 years, those without ischaemia and LGE experienced a low annual rate of hard events (<1%), across all BMI strata. In patients with obesity, both ischaemia [hazard ratio (HR): 2.14; 95% confidence interval (CI): 1.30-3.50; P = 0.003] and LGE (HR: 3.09; 95% CI: 1.83-5.22; P < 0.001) maintained strong adjusted association with the primary outcome in a multivariable Cox regression model. Downstream referral rates to coronary angiography, revascularization, and cost of care spent on ischaemia testing did not significantly differ within the BMI categories.

CONCLUSION

In this large multicentre registry, elevated BMI did not negatively impact the diagnostic quality and the effectiveness of risk stratification of patients referred for stress CMR.

The obesity paradox in the stress echo lab: fat is better for hearts with ischemia or coronary microvascular dysfunction

BACKGROUND

Obesity is an independent risk factor for coronary artery disease (CAD), but once CAD has developed it has been associated with improved survival ("obesity paradox").

AIM

To assess how obesity affects prognosis in patients with or without inducible ischemic regional wall motion abnormalities (RWMA) and/or abnormal coronary flow velocity reserve (CFVR) during stress echocardiography (SE).

METHODS

In an observational retrospective two- center study design, we analyzed 3249 consecutive patients (1907 men; age 66 ± 12 years; body mass index, BMI, 26.9 ± 4.1 kg/m²) with known (n = 1306) or suspected (n = 1943) CAD who underwent dipyridamole SE with simultaneous evaluation of RWMA and CFVR. All-cause death was the outcome end-point.

RESULTS

1075 patients were lean (BMI 18.5-24.9 kg/m²), 1523 overweight (BMI 25.0-29.9 kg/m²), and 651 obese (≥30.0 kg/m²). Ischemic test result for RWMA occurred in 28 (3%) lean, 69 (4%) overweight, and 28 (4%) obese patients (p = 0.03). An abnormal CFVR (≤2.0) was found in 281 (26%) lean, 402 (26%) overweight and 170 (26%) obese patients (p = 0.99). During 68 ± 44 months of follow-up, 496 (15%) patients died. At multivariable Cox analysis, BMI ≥ 30 was an independent predictor of reduced mortality in the 878 patients with stress-induced (≥2 segments) RWMA and/or CFVR abnormality (HR 0.58, 95% CI 0.40-0.84; p = 0.003), while showed no effect at univariate analysis in the 2371 patients with no RWMA and normal CFVR (HR 1.04, 95% CI 0.74-1.46; p = 0.84).

CONCLUSIONS

Obesity exerts a "paradoxical" protective effect in patients with stress-induced ischemia and/ or coronary microvascular dysfunction, and shows a neutral effect in patients with normal CFVR and no stress-induced RWMA.

The Utility of Echocardiography for Non-ST-Segment Elevation Myocardial Infarction: A Retrospective Study

Objective:

The objectives were to assess factors associated with a higher likelihood of predicting acute coronary atherothrombosis (ACA) in non-ST-segment elevation myocardial infarction (NSTEMI), evaluate the impact of adding echocardiographic data, and develop an algorithm that would reduce overutilization of emergent angiography.

Methods:

Data were retrospectively analyzed on a patient cohort presenting to an emergency department of an urban community hospital with NSTEMI from October 1, 2015, to July 31, 2018. The inclusion criterion was any adult patient with a first-time, primary diagnosis of NSTEMI without high-risk features. The main outcome variables were the presence of ACA on angiography.

Results:

Seventy-three patients with NSTEMI were included in this study. Logistic regression analysis identified the following independent variables useful for predicting ACA: age, wall motion abnormality on echo, and levels of low-density lipoprotein. The model’s overall fit was highly significant ( P = .0012).

Conclusion:

An integrative approach was demonstrated for the management of patients with NSTEMI presenting to the hospital. Although the positive predictive value of echo in predicting ACA was limited, when combined with demographic attributes and risk factors, it proved to be successful in determining the need for angiography in patients with NSTEMI.

Clinical practice of contrast echocardiography: recommendation by the European Association of Cardiovascular Imaging (EACVI) 2017

Contrast echocardiography is widely used in cardiology. It is applied to improve image quality, reader confidence and reproducibility both for assessing left ventricular (LV) structure and function at rest and for assessing global and regional function in stress echocardiography. The use of contrast in echocardiography has now extended beyond cardiac structure and function assessment to evaluation of perfusion both of the myocardium and of the intracardiac structures. Safety of contrast agents have now been addressed in large patient population and these studies clearly established its excellent safety profile. This document, based on clinical trials, randomized and multicentre studies and published clinical experience, has established clear recommendations for the use of contrast in various clinical conditions with evidence-based protocols.

Stress echocardiography in contemporary clinical cardiology: practical considerations and accreditation

Stress echocardiography is a widely utilised test in patients with known or suspected coronary artery disease (CAD), valvular heart disease and cardiomyopathies. Its advantages include the ubiquitous availability of echocardiography, lack of ionising radiation, choice of physiological or pharmacological stressors, good diagnostic accuracy and robust supporting evidence base. SE has evolved significantly as a technique over the past three decades and has benefitted considerably from improvements in overall image quality (superior resolution), machine technology (e.g. digital cine-loop acquisition and side-by-side image display) and development of second-generation ultrasound contrast agents that have improved reader confidence and diagnostic accuracy. The purpose of this article is to review the breadth of SE in contemporary clinical cardiology and discuss the recently launched British Society of Echocardiography (BSE) Stress Echocardiography accreditation scheme.

Anaesthetic Preparation of Obese Patients: Current Status on Optimal Work-up

PURPOSE OF REVIEW

With the prevalence of obesity rapidly growing, bariatric anaesthesia becomes everyday anaesthesia rather than a subspecialty. In this review, we are aiming to draw attention to this complex group of patients and their comorbidities, relevant to everyday practice for contemporary anaesthetists.

RECENT FINDINGS

We wanted to focus greatly on sleep-related breathing disorders, because preoperative screening, diagnosis and treatment of the aforementioned make a huge impact in the improvement of preoperative morbidity and mortality, including positive effects on the cardiovascular system. The overview is touching on main obesity-related comorbidities and guides the anaesthetist and associated health professionals on how to approach and manage them. A multidisciplinary approach widely used in bariatric care may be adopted in the care of obese patients in order to reduce preoperative morbidity and mortality. We advocate the early involvement of the anaesthetic team in the preoperative assessment of obese patients in order to achieve appropriate risk stratification and optimise the care.

Management of cardiovascular diseases in patients with obesity

The management of cardiovascular diseases (CVD) in patients with obesity presents numerous challenges. Obesity has a negative effect on almost all of the major CVD risk factors, and adversely influences cardiovascular structure and function. Patients who are overweight or obese have a higher incidence of almost all CVDs compared with patients who are of normal weight. However, those who are overweight or obese seem to have a better short-term and medium-term prognosis after major CVD events and interventional procedures or cardiac surgeries than leaner patients, a phenomenon termed the 'obesity paradox'. In considering the mechanisms underlying this paradox, we review evidence of the deleterious consequences of obesity in patients with coronary heart disease, and the limited data on the benefits of weight loss in patients with CVD. Additional studies are needed on the efficacy of purposeful weight loss on cardiovascular outcomes to determine the ideal body composition for patients with CVD.

Effect of Coronary Revascularization on the Prognostic Value of Stress Myocardial Contrast Wall Motion and Perfusion Imaging

Background

The assessment of myocardial perfusion (MP) and wall motion (WM) using contrast dipyridamole echocardiography (cSE‐WMP) improves the sensitivity to detect coronary artery disease and the stratification of cardiac events, but its long‐term value for fatal and nonfatal ischemic cardiac events, also with respect to patients undergoing revascularization or not, remains to be determined.

Methods and Results

One‐thousand three‐hundred and twenty‐nine patients with suspect or known CAD who underwent cSE‐WMP were followed for a median 5.5 years. The independent prognostic value of cSE‐WMP regarding cardiac death or nonfatal myocardial infarction was related to stress WM and MP, rest ejection fraction, clinical risk factors, and medications. Patients revascularized after cSE‐WMP were separately analyzed to determine whether the procedure influenced outcome and whether this depends on cSE‐WMP results. A total of 125 cardiac fatal and nonfatal ischemic events (9.4%) occurred during the follow‐up (61 deaths, 64 myocardial infarctions). The 5‐year event rate with normal MP and WM was 5.9%, 9.9% with isolated MP defects (normal WM), and 15.5% with both MP and WM abnormalities. In patients not undergoing revascularization (n=1111), reversible MP defects added discrimination value over WM response and clinical factors/medication data (P=0.001), while in the cohort undergoing revascularization (n=218), cSE‐WMP results did not influence outcome.

Conclusions

cSE‐WMP, with both contrast MP and WM assessments, provides independent, incremental prognostic information regarding ischemic cardiac events at 5 years in patients with known or suspected coronary artery disease. Revascularization reduces cardiac events after an abnormal cSE‐WMP, resulting in outcomes not different from those in patients with normal cSE‐WMP.

Stress echocardiography in patients with morbid obesity

The incidence of significant obesity is rising across the globe. These patients often have a clustering of cardiovascular risk factors and are frequently referred for noninvasive cardiac imaging tests. Stress echocardiography (SE) is widely used for assessment of patients with known or suspected coronary artery disease (CAD), but its clinical utility in morbidly obese patients (in whom image quality may suffer due to body habitus) has been largely unknown. The recently published Stress Ultrasonography in Morbid Obesity (SUMO) study has shown that SE, when performed appropriately with ultrasound contrast agents (whether performed with physiological or pharmacological stress), has excellent feasibility and appropriately risk stratifies morbidly obese patients, including identification of patients who require revascularization. This article reviews the evidence supporting the use of echocardiographic techniques in morbidly obese patients for assessment of known or suspected CAD and briefly discusses other noninvasive modalities, including magnetic resonance and nuclear techniques, comparing and contrasting these techniques against SE.