Prognostic Role of Metabolic Exercise Testing in Heart Failure

Heart failure is a clinical syndrome with significant heterogeneity in presentation and severity. Serial risk-stratification and prognostication can guide management decisions, particularly in advanced heart failure, when progression toward advanced therapies or end-of-life care is warranted. Each currently utilized prognostic marker carries its own set of challenges in acquisition, reproducibility, accuracy, and significance. Left ventricular ejection fraction is foundational for heart failure syndrome classification after clinical diagnosis and remains the primary parameter for inclusion in most clinical trials; however, it does not consistently correlate with symptoms and functional capacity, which are also independently prognostic in this patient population. Utilizing the left ventricular ejection fraction as the sole basis of prognostication provides an incomplete characterization of this condition and is prone to misguide medical decision-making when used in isolation. In this review article, we survey and exposit the important role of metabolic exercise testing across the heart failure spectrum, as a complementary diagnostic and prognostic modality. Metabolic exercise testing, also known as cardiopulmonary exercise testing, provides a comprehensive evaluation of the multisystem (i.e., neurological, respiratory, circulatory, and musculoskeletal) response to exercise performance. These differential responses can help identify the predominant contributors to exercise intolerance and exercise symptoms. Additionally, the aerobic exercise capacity (i.e., oxygen consumption during exercise) is directly correlated with overall life expectancy and prognosis in many disease states. Specifically in heart failure patients, metabolic exercise testing provides an accurate, objective, and reproducible assessment of the overall circulatory sufficiency and circulatory reserve during physical stress, being able to isolate the concurrent chronotropic and stroke volume responses for a reliable depiction of the circulatory flow rate in real time.

Mortality associated with antiarrhythmic medication for atrial fibrillation among patients with left ventricular hypertrophy

BACKGROUND

Atrial fibrillation (AF) guidelines recommend amiodarone as the preferred antiarrhythmic medication (AAM) in patients with left ventricular hypertrophy (LVH), due to potential pro-arrhythmic risk with other AAM. However, there are limited data to support this assertion.

METHODS

We retrospectively analyzed the records of 8204 patients who were prescribed AAM for AF and had transthoracic echocardiogram (TTE) at the multicenter, VA Midwest Health Care Network from 2000 to 2021. We excluded patients without LVH (septal or posterior wall dimension ≤1.4 cm). The primary outcome variable was all-cause mortality during antiarrhythmic therapy or within 6 months after stopping it. Propensity-stratified analyses were performed between amiodarone versus non-amiodarone (Vaughan-Williams Class I and III) AAM.

RESULTS

A total of 1277 patients with LVH (mean age 70.2 ± 9.5 years) were included in the analysis. Of these, 774 (60.6%) were prescribed amiodarone. Baseline characteristics of the two comparison groups were similar after propensity adjustment. After a median 1.40 years of follow-up, 203 (15.9%) patients died. Incidence rates per 100 patient-year follow-up was 9.02 (7.58-10.66) for amiodarone and 4.98 (3.91-62.56) for non-amiodarone. In propensity-stratified analysis, amiodarone use was associated with 1.58 times higher risk of mortality (95% CI 1.03-2.44; p = .038). Sub-group analysis in 336 (26.3%) patients with severe LVH showed no difference in mortality (HR 1.41, 95% CI 0.82-2.43, p = .21).

CONCLUSION

Among patients with AF and LVH, amiodarone was associated with a significantly higher mortality risk than other AAM.

Supraglottic Airway Devices are Associated with Asphyxial Physiology After Prolonged CPR in Patients with Refractory Out-of-Hospital Cardiac Arrest Presenting for Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Multiple randomized clinical trials have compared specific airway management strategies during ACLS with conflicting results. However, patients with refractory cardiac arrest died in almost all cases without the availability of extracorporeal cardiopulmonary resuscitation (ECPR). Our aim was to determine if endotracheal intubation (ETI) was associated with improved outcomes compared to supraglottic airways (SGA) in patients with refractory cardiac arrest presenting for ECPR.

METHODS

We retrospectively studied 420 consecutive adult patients with refractory out-of-hospital cardiac arrest due to shockable presenting rhythms presenting to the University of Minnesota ECPR program. We compared outcomes between patients receiving ETI (n=179) and SGA (n=204). The primary outcome was the pre-cannulation arterial PaO₂ upon arrival to the ECMO cannulation center. Secondary outcomes included neurologically favorable survival to hospital discharge and eligibility for VA-ECMO based upon resuscitation continuation criteria applied upon arrival to the ECMO cannulation center.

RESULTS

Patients receiving ETI had significantly higher median PaO₂ (71 vs. 58 mmHg, p=0.001), lower median PaCO₂ (55 vs. 75 mmHg, p<0.001), and higher median pH (7.03 vs. 6.93, p<0.001) compared to those receiving SGA. Patients receiving ETI were also significantly more likely to meet VA-ECMO eligibility criteria (85% vs. 74%, p=0.008). Of patients eligible for VA-ECMO, patients receiving ETI had significantly higher neurologically favorable survival compared to SGA (42% vs. 29%, p=0.02).

CONCLUSIONS

ETI was associated with improved oxygenation and ventilation after prolonged CPR. This resulted in increased rate of candidacy for ECPR and increased neurologically favorable survival to discharge with ETI compared to SGA. Short Title: Airway Effects in Refractory Cardiac Arrest.

Agreement of Proximal Thoracic Aorta Size by Two-Dimensional Transthoracic Echocardiography and Magnetic Resonance Angiography

There is currently a lack of uniformity in methods of aortic diameter measurements across different imaging modalities. In this study, we sought to evaluate the accuracy of transthoracic echocardiography (TTE) in comparison with magnetic resonance angiography (MRA) for the measurement of proximal thoracic aorta diameters. This is a retrospective analysis of 121 adult patients at our institution who had TTE and electrocardiogram  (ECG)-gated MRA performed within 90 days of each other between 2013 and 2020. Measurements were made at the level of sinuses of Valsalva (SoV), sinotubular junction (STJ), and ascending aorta (AA) using leading edge-to-leading edge (LE) convention for TTE and inner-edge-to-inner-edge (IE) convention for MRA. Agreement was assessed using Bland-Altman methods. Intra- and interobserver variability were assessed by intraclass correlation. The average age of patients in the cohort was 62 years, and 69% of patients were male. The prevalence of hypertension, obstructive coronary artery disease, and diabetes was 66%, 20%, and 11%, respectively. The mean aortic diameter by TTE was SoV 3.8 ± 0.5 cm, STJ 3.5 ± 0.4 cm, and AA 4.1 ± 0.6 cm. The TTE-derived measurements were larger than the MRA ones by 0.2 ± 2 mm, 0.8 ± 2 mm, and 0.4 ± 3 mm at the level of SoV, STJ, and AA, respectively, but the differences were not statistically significant. There were no significant differences in the aorta measurements by TTE compared with MRA, when stratified by gender. In conclusion, transthoracic echocardiogram-derived proximal aorta measurements are comparable to MRA measurements. Our study validates current recommendations that TTE is an acceptable modality for screening and serial imaging of the proximal aorta.

Multiple cutaneous and mucosal lesions in a patient with cocaine-levamisole-induced vasculopathy syndrome

Levamisole is an adulterant found in nearly 70% of cocaine in the United States. The concomitant use of levamisole and cocaine leads to a distinct clinical syndrome that typically manifests as agranulocytosis, leukocytoclastic vasculitis, and elevated antineutrophil cytoplasmic antibody (ANCA) levels. Systemic involvement has also been rarely reported with this syndrome. This is a case of a 51-year-old woman with chronic cocaine use who initially presented with multiple cutaneous ulcerations and was later found to have pulmonary and renal involvement. Infectious workup was unrevealing and autoimmune workup revealed highly elevated levels of perinuclear ANCA. Due to continuous cocaine use despite counseling, the patient was readmitted with worsening pulmonary and renal manifestations requiring initiation of immunosuppressive therapy.

Massive pulmonary embolism presenting initially as acute psychosis

This is a case of a 68-year-old man with Parkinson’s disease who was admitted in the psychiatry floor for new-onset aggressive behaviour and hallucinations. On the third day of hospitalisation, he suddenly developed dyspnoea followed by an ECG showing atrial fibrillation with rapid ventricular response. A few seconds later, he went into cardiac arrest; he was resuscitated after multiple rounds of Advanced Cardiovascular Life Support. A transthoracic echo showed hypokinetic and enlarged right ventricle. A CT Chest showed a saddle embolus. Patient was provided with systemic thrombolysis, which led to an improvement in his haemodynamic status. Interestingly, his psychotic symptoms also improved. In this paper, we present and review how pulmonary embolism can be associated with acute psychosis.

Patent foramen ovale and ascending aortic aneurysm causing the platypnea-orthodeoxia syndrome

Patent foramen ovale (PFO) is present in about 25% of the population. Platypnea-orthodeoxia syndrome (POS), which is dyspnea and hypoxemia in the upright position that is relieved when supine, is a rare manifestation of PFO. We describe a case of a 74-year-old woman who presented with new-onset hypoxia. A PFO and a dilated aorta causing POS were found on workup. Symptoms were resolved after undergoing percutaneous PFO closure. This case highlights the mechanism by which an ascending aortic aneurysm can alter hemodynamics through an existing PFO, leading to symptoms of a previously clinically insignificant PFO, and emphasizes how early recognition of POS allows for appropriate intervention.