Christopher Austin

Echocardiographic Assessment of Estimated Right Atrial Pressure and Size Predicts Mortality in Pulmonary Arterial Hypertension

BACKGROUND Elevated mean right atrial pressure (RAP) measured by cardiac catheterization is an independent risk factor for mortality. Prior studies have demonstrated a modest correlation with invasive and noninvasive echocardiographic RAP, but the prognostic impact of estimated right atrial pressure (eRAP) has not been previously evaluated in patients with pulmonary arterial hypertension (PAH). METHODS A retrospective analysis of 121 consecutive patients with PAH based on right-sided heart catheterization and echocardiography was performed. The eRAP was calculated by inferior vena cava diameter and collapse using 2005 and 2010 American Society of Echocardiography (ASE) definitions. Accuracy and correlation of eRAP to RAP was assessed. Kaplan-Meier survival analysis by eRAP, right atrial area, and Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL Registry) risk criteria as well as univariate and multivariate analysis of echocardiographic findings was performed. RESULTS Elevation of eRAP was associated with decreased survival time compared with lower eRAP (P < .001, relative risk = 7.94 for eRAP > 15 mm Hg vs eRAP ≤ 5 mm Hg). Univariate analysis of echocardiographic parameters including eRAP > 15 mm Hg, right atrial area > 18 cm², presence of pericardial effusion, right ventricular fractional area change < 35%, and at least moderate tricuspid regurgitation was predictive of poor survival. However, multivariate analysis revealed that eRAP > 15 mm Hg was the only echocardiographic risk factor that was predictive of mortality (hazard ratio = 2.28, P = .037). CONCLUSIONS Elevation of eRAP by echocardiography at baseline assessment was strongly associated with increased risk of death or transplant in patients with PAH. This measurement may represent an important prognostic component in the comprehensive echocardiographic evaluation of PAH.

The application of Big Data in medicine: current implications and future directions.

Since the mid 1980s, the world has experienced an unprecedented explosion in the capacity to produce, store, and communicate data, primarily in digital formats. Simultaneously, access to computing technologies in the form of the personal PC, smartphone, and other handheld devices has mirrored this growth. With these enhanced capabilities of data storage and rapid computation as well as real-time delivery of information via the internet, the average daily consumption of data by an individual has grown exponentially. Unbeknownst to many, Big Data has silently crept into our daily routines and, with continued development of cheap data storage and availability of smart devices both regionally and in developing countries, the influence of Big Data will continue to grow. This influence has also carried over to healthcare. This paper will provide an overview of Big Data, its benefits, potential pitfalls, and the projected impact on the future of medicine in general and cardiology in particular.

Retained cardiac implantable electronic device fragments are not associated with magnetic resonance imaging safety issues, morbidity, or mortality after orthotopic heart transplant

Background Cardiac implantable electronic device therapy (CIED) has revolutionized treatment for advanced heart failure. Most patients considered for orthotopic heart transplantation (OHT) are treated with implantable cardioverter defibrillators, cardiac resynchronization therapy, or both. These CIEDs are surgically extracted at the time of transplant. Occasionally, CIEDs are incompletely removed. Little is known about the outcomes of post‐OHT patients with retained CIED fragments. Methods We identified 200 consecutive patients that underwent OHT at our institution between April 2006 and December 2014 and performed a retrospective analysis of available radiographic images and clinical records. Chest radiographs prior to and following OHT were reviewed for the presence of CIED or retained CIED fragments. The outcomes of patients with retained CIED fragments that had subsequent magnetic resonance imaging (MRI) studies performed were further investigated. Results One hundred eighty of 200 patients were identified as having CIED prior to OHT, of which 29 had retained CIED fragments after OHT. Most retained CIED fragments originated from superior vena cava defibrillator coils. There were no adverse events in the retained CIED fragment cohort, and survival was unaffected. Ten patients with retained CIED fragments safely underwent a total of 28 MRIs after OHT, all of diagnostic quality. Conclusion Retained CIED fragments are not associated with adverse events or increased mortality after OHT. Diagnostic MRI has been safely performed in patients with retained CIED fragments after incomplete device extraction. Retrieval of these fragments prior to MRI does not appear warranted given the demonstrated safety and preserved image quality in this population.

Screening for connective tissue disease in pulmonary arterial hypertension

Objectives To evaluate the utility of anti-nuclear antibody (ANA) levels in distinguishing the cause of pulmonary arterial hypertension as idiopathic (IPAH) or connective tissue disease related (CTD-PAH). Methods We retrospectively identified patients with IPAH or CTD-PAH seen between 2010 and 2012 at our institution. Medical records were reviewed for demographic and clinical data and laboratory values. Results Of 115 patients identified, 65 (56%) had IPAH and 50 (44%) had CTD-PAH. The mean age was 59 years and most of the patients (76%) were women. Most patients (64%) were in World Health Organization functional class III or IV. Compared with the IPAH group, the CTD-PAH group had significantly increased B-type natriuretic peptide levels (635 vs 325 pg/mL; P = 0.02) and decreased pulmonary vascular resistance (6 vs 9 WU; P = 0.04). The median ANA level was significantly higher in the CTD-PAH group than the IPAH group (7 vs 0 U; P < 0.001). The area under the receiver operating characteristic curve for a positive ANA to predict CTD-PAH was 0.91 (P < 0.001). A cutoff of 5 U for predicting ANA provided an optimal specificity of 94% and a sensitivity of 70%. The resulting likelihood ratio using the same cutoff was 12 (P < 0.001), or a positive predictive value of 91% with a negative predictive value of 79%. Conclusions In this selected cohort of patients, a quantitative ANA value >5 U may be useful in distinguishing CTD-PAH from IPAH, but a lower level does not confidently exclude CTD-PAH.

A heart of stone: A case of acute development of cardiac calcification and hemodynamic collapse

Acute cardiac calcification is a clinical entity that may develop over days to months and is usually localized to areas of healed myocardial infarction, cardiac surgery or trauma. We present an unusual case of rapidly developing non-ischemic cardiac calcification in the setting of sepsis and end stage renal disease resulting in acute diastolic dysfunction and cardiac collapse diagnosed by computed tomography (CT) and confirmed by autopsy. We propose that dedicated cardiac CT may provide the most accurate means to detect cardiac calcification.

Assessing the available techniques for testing myocardial viability: what does the future hold?

Left ventricular dysfunction in the setting of severe coronary artery disease poses a major diagnostic and therapeutic dilemma. While this clinical scenario is generally associated with poor outcomes, some but not all patients benefit from coronary revascularization. For example, patients with severe, transmural myocardial infarctions may derive little or no functional benefit from revascularization, as the underlying myocardium is irreversibly scarred. Furthermore, these patients may be exposed to high procedural risks with a low likelihood of deriving any perceivable benefit. Conversely, hibernating myocardium reflects a substrate whereby the nonfunctioning myocytes are chronically ischemic but may be viable. Existing data are somewhat inconclusive with regard to the benefits of performing viability testing in patients with ischemic cardiomyopathy. While this testing may predict regional and global functional myocardial recovery, the ability of viability studies to predict survival and prognosis remains unproven in prospective studies to date. Yet, viability testing may still be a valuable tool to guide therapeutic options in selected patients. A variety of noninvasive viability tests are available and newer technologies, such as PET and cardiac MRI, are likely to advance the scientific field in years to come.

Pacemaker Placement in Patients with Stroke-Mediated Autonomic Dysregulation

Lateral medullary syndrome (LMS) is an ischemic disease of the medulla oblongata, which involves the territory of the posterior inferior cerebellar artery. Lateral medullary syndrome is often missed as the cause of autonomic dysregulation in patients with recent brain stem stroke. Due to the location of the baroreceptor regulatory center in the lateral medulla oblongata, patients with LMS occasionally have autonomic dysregulation-associated clinical manifestations. We report a case of LMS-associated autonomic dysregulation. The case presented as sinus arrest and syncope, requiring permanent pacemaker placement. A dual-chamber pacemaker was placed, after failure of conservative measures to alleviate the patients symptoms. Our case shows the importance of recognizing LMS as a potential cause for life-threatening arrhythmias, heart block, and symptomatic bradycardia. Placement of permanent pacemaker may be necessary in some patients with LMS presenting with syncope, secondary to sinus arrest.

High-risk echocardiographic features predict mortality in pulmonary arterial hypertension

Aims Echocardiography is the most common imaging modality for assessment of the right ventricle in patients with pulmonary arterial hypertension (PAH). Echocardiographic parameters were identified as independent risk factors for mortality in the Registry to Evaluate Early and Long‐term PAH Disease Management (REVEAL) and other PAH cohorts. We sought to identify readily obtained echocardiographic features associated with PAH survival. Methods and results Retrospective analysis of 175 patients with Group 1 was performed. Baseline clinical and laboratory assessment including REVEAL risk criteria were obtained and standard 2‐Dimensional and Doppler echocardiography performed at baseline was reviewed. Univariate and multivariate analyses of echocardiographic parameters were performed. Estimated right atrial pressure> 15 mmHg (HR 2.39, P = .02), tricuspid regurgitation ≥ moderate (HR 2.16, P = .04), and presence of pericardial effusion (HR 1.8, P = .05) were identified as independent, high‐risk echocardiographic features in PAH. A validation cohort of 677 patients was identified and Kaplan–Meier survival analysis was performed in both cohorts. High‐risk echocardiographic features stratified survival curves of both cohorts (P < .01 for all). The presence of 3 high‐risk echocardiographic features greatly increased risk of 1‐year (RR 4.86) and 3‐year (RR 3.35) mortality (P < .05 for both). Conclusion Estimated right atrial pressure> 15, tricuspid regurgitation ≥ moderate, and presence of pericardial effusion are high‐risk echocardiographic features in PAH. When seen in combination, these features greatly increase risk of mortality in PAH and may lead to more timely enhanced therapy for patients identified as having an increased risk for death.

Innovative pacing: Recent advances, emerging technologies, and future directions in cardiac pacing

The field of cardiovascular medicine is rapidly evolving as advancements in technology and engineering provide clinicians new and exciting ways to care for an aging population. Cardiac pacing, in particular, has seen a series of game-changing technologies emerge in the past several years spurred by low-power electronics, high density batteries, improved catheter delivery systems and innovative software design. We look at several of these emerging pacemaker technologies, discussing the rationale, current state and future directions of these pioneering developments in electrophysiology.

Use of cardiac magnetic resonance imaging for alcohol septal ablation in hypertrophic obstructive cardiomyopathy

Abstract This is a report of a 58-year-old man with severe hypertrophic obstructive cardiomyopathy who underwent alcohol septal ablation to relieve symptoms due to severe left ventricular outflow obstruction. Cardiac magnetic resonance was performed before and after the procedure. This case highlights the potential use of cardiac magnetic resonance imaging in the surgical planning of alcohol septal ablation as well as following the procedure to assess for complications and morphological changes.