Richa Agarwal

Evaluation of the American College of Cardiology Foundation/American Society of Nuclear Cardiology appropriateness criteria for SPECT myocardial perfusion imaging.

Background. The American College of Cardiology Foundation/American Society of Nuclear Cardiology appropriateness criteria (AC) were created to guide responsible use of single photon emission computed tomography (SPECT). Clinical applicability of the AC has not been evaluated.Methods and Results. Indications for testing were determined in 1209 patients and categorized as having appropriate, uncertain, or inappropriate indications; the specialty of the ordering physician was noted. There were 940 (80%) appropriate, 154 (13%) inappropriate, and 79 (7%) uncertain tests; 36 tests were labeled “no category,” as these were ordered for indications not clearly addressed in the AC. Inappropriate studies had more normal and lower summed stress scores, although there remained a high proportion of abnormal SPECT studies in this group (26% of women and 50% of men). Women had lower summed stress scores and more normal tests in the appropriate and inappropriate groups. Studies ordered by anesthesiologists for preoperative evaluation were more likely to be deemed inappropriate than other specialty groups.Conclusion. In evaluating the AC in a single-center academic setting, the majority of studies are appropriate, but a large proportion of ordered SPECT studies were categorized as uncertain, inappropriate, or no category. Although the inappropriate studies showed less ischemia than other groups, especially in women, a substantial portion of these studies (32%) were abnormal.

Current therapeutics and practical management strategies for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) develops from an abnormal interaction between the endothelium and smooth muscle cells in the pulmonary vasculature and is characterized by a progressive rise in pulmonary vascular resistance resulting from vascular remodeling, vasoconstriction, and cellular proliferation. Currently, 3 classes of drugs are approved for the treatment of PAH based on results from small short-term clinical trials-prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. The pharmacologic management of PAH is rapidly evolving as newer therapeutic targets that stabilize or reverse pulmonary vascular disease and target right ventricular function are being sought and as clinical practice patterns shift in favor of earlier diagnosis and aggressive treatment. This manuscript will review the practical management aspects of currently approved PAH treatments and briefly discuss combination therapy and novel pharmacologic targets. In addition, the treatment of acute right ventricular failure and evidence (or lack thereof) for therapies in non-PAH pulmonary hypertension, such as pulmonary hypertension from left side of the heart disease, are addressed.

Risk assessment in pulmonary hypertension associated with heart failure and preserved ejection fraction

BACKGROUND Pulmonary hypertension (PH) is common in patients with left heart failure (HF), especially those with HF and preserved ejection fraction (HFpEF). However, there is limited data on risk stratification in these patients. METHODS Baseline clinical and hemodynamic variables of 339 patients with World Health Organization (WHO) Group 2 PH, 90% of whom had HFpEF, were studied to derive a multivariate Cox proportional hazards model. A simplified prognostic risk score was created based on the outcome of all-cause mortality. Nine predictors, significant after stepwise multivariable regression (p < 0.05), were used to create the risk score. Components of the risk score were functional class, diastolic blood pressure, pulmonary artery saturation, interstitial lung disease, hypotension on initial presentation, right ventricular hypertrophy, diffusion capacity of the lung for carbon monoxide, and 2 serum creatinine variables (≤ 0.9 mg/dl and ≥ 1.4 mg/dl). RESULTS Overall 2-year survival was 73.8% ± 2.4% in the derivation cohort, and 87.5% ± 2.3%, 66.4% ± 4.9%, and 24.4% ± 6.7% for risk scores of 0 to 2, 3 to 4, and 5+, respectively (p < 0.0001 for the trend), with a C-index of 0.76 (95% confidence interval [CI], 0.71-0.81). The risk score was validated in 2 independent PH-HFpEF cohorts: 179 patients with a C-index of 0.68 (95% CI, 0.55-0.80) and 117 patients with a C-index of 0.68 (95% CI, 0.53-0.83). For the 3 cohorts combined (N = 635), the overall C-index was 0.72 (95% CI 0.68-0.76). In all 3 cohorts individually and in the 3 cohorts combined, the risk score predicted death (hazard ratio, 1.4-1.6; p < 0.01). CONCLUSIONS Several clinical factors independently predict death in PH-HFpEF confirmed by validation. A novel risk score composed of these factors can be used to determine prognosis and may be useful in making therapeutic decisions.

Treadmill testing improves survival prediction models in pulmonary arterial hypertension

BACKGROUND Six-minute walk distance (6MWD) is used in the REVEAL equation to predict 1-year survival for patients with pulmonary arterial hypertension. We sought to determine whether exercise treadmill testing (ETT) could be used in its place. METHODS This was a single-center study in which 449 patients were enrolled. The variables predictive of survival in the REVEAL equation were evaluated and compared with survival predicted by the REVEAL equation without an exercise measure and a revised equation using ETT. RESULTS The addition of ETT to the equation improved the predictive ability of the REVEAL equation in the high- and low-risk patient groups. CONCLUSION The study findings suggest that the addition of ETT parameters to the REVEAL prognostic equation improves the predictive value of the equation when 6-minute walk distance is unavailable.

Prognostication in Pulmonary Arterial Hypertension

Despite the advances in diagnostic and treatment strategies, and contemporary survival estimates suggesting improved outcomes, the prognosis of patients with pulmonary arterial hypertension (PAH) remains poor. To date, there is no consensus on which prognostic variables or risk prediction strategies best predict survival, at baseline and at different time points in the disease course. Even less clear is whether current prognostic variables accurately reflect disease severity and can sufficiently guide therapeutic decisions. This article reviews the most common factors used for prognostication in PAH, emphasizing that proper strategies for identifying patients at greatest risk are paramount.

Can real-time three-dimensional echocardiography be used reliably for the assessment of left ventricular dyssynchrony?

The assessment of LV dyssynchrony through a variety of advanced imaging modalities has garnered substantial interest, as current dyssynchrony markers remain equivocal for predicting response to CRT in patients with advanced heart failure. Current recommendations support the use of CRT in symptomatic patients with moderate-to-severe heart failure, New York Heart Association functional class III or IV, QRS duration greater or equal 120 ms and an ejection fraction less or equal to 35%, who have been optimized with medical therapy. This device-based therapy has important therapeutic benefits, including functional and clinical.