Robert Berkowitz

Differentiating Pulmonary Arterial and Pulmonary Venous Hypertension and the Implications for Therapy

Pulmonary arterial and pulmonary venous hypertension develop from distinctly different etiologies. Pulmonary arterial hypertension (PAH), or Group 1 pulmonary hypertension (PH), is a precapillary PH that arises idiopathically or as the result of a divergent array of causes, including connective tissue disease. Pulmonary venous hypertension (PVH), or Group 2 PH, primarily manifests as a postcapillary PH in the setting of left heart failure or valvular disease. A subset of PVH patients, however, develop a reactive precapillary component of PH that mimics PAH. These patients can be misdiagnosed as having Group 1 PH by 2-dimensional echocardiography and are sometimes treated as such, which leads to exacerbation of heart failure. Therefore, 2-dimensional or Doppler echocardiography alone cannot be used to differentiate between these two classifications of PH. This highlights the need for right heart catheterization in the clinical assessment and diagnostic work-up of PH. The combination of imaging and invasive hemodynamic assessment by right heart catheterization provides the best diagnostic approach to ensure proper delineation of pulmonary arterial and pulmonary venous hypertension, and in turn leads to appropriate treatment.

Determinants of right ventricular failure in patients admitted with acute left heart failure.

Pulmonary hypertension, which may lead to right ventricular (RV) failure, increases with left ventricular (LV) diastolic dysfunction severity. The prevalence and determinants of RV failure were analyzed in 120 patients admitted with acute left heart (LH) failure. Patients were divided into RV failure (n=50) and non-RV failure (n=70) groups. The prevalence of RV failure was found to be 42%. In both groups, two thirds of the patients had isolated LV diastolic dysfunction and the rest had combined LV systolic and diastolic dysfunction. Patients in the RV failure group were characterized by higher LV diastolic grade (2.2 ± 0.6 vs 1.84 ± 0.7; P=.0070), pulmonary artery systolic pressure (PASP; 57.8 ± 15.3 vs 50.14 ± 12.1 mm Hg; P=.0028), right atrial enlargement (92% vs 25.7%; P=.000001), and more-than-moderate tricuspid regurgitation (58% vs 27.1%; P=.0006). RV failure is a frequent finding in patients with advanced LH failure. It is strongly associated with the severity of LV diastolic dysfunction and the severity of PASP.

The Use of Midodrine in Patients With Advanced Heart Failure

In many patients, the treatment of heart failure (HF) cannot be optimized because of pre-existing or treatment-induced hypotension. Midodrine, a peripheral alpha1-adrenergic agonist may allow for up-titration of neurohormonal antagonist therapy leading to improved outcomes. Ten consecutive patients with HF due to systolic dysfunction and symptomatic hypotension interfering with optimal medical therapy were started on midodrine. After a 6-month follow-up, a higher percentage of patients were on optimal HF therapy (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker mg % of optimal dose 20% vs 57.5%; P<.001) (beta-blockers mg % optimal dose 37.5% vs 75%; P<.001) (spironolactone/eplerenone mg % 43.7% vs 95%; P<.001). This led to an improvement in left ventricular ejection fraction (baseline 24+/-9.4 vs 32.2+/-9.9; P<.001) and clinical outcomes, with a significant reduction in total hospital admissions (32 vs 12; P=.02) and total hospital days (150 vs 58; P=.02).

Milrinone Dosing and a Culture of Caution in Clinical Practice

Milrinone is an invaluable agent in the treatment of end-stage heart failure patients who are refractory to optimal medical therapy. In addition to its use in acute decompensated heart failure, milrinone can also be employed as a home infusion therapy or a bridge to cardiac transplant. Concerns about its adverse effects, such as an increased risk of arrhythmias and hypotension, often limit the doses of milrinone used in clinical practice. In addition, milrinone is infrequently used or avoided entirely in patients with acute renal failure or end-stage renal disease because the drug is primarily cleared by renal excretion. Despite these concerns, studies that comprehensively reconcile the dose–response relationship and adverse events are scarce, and no clear provisions exist to guide milrinone dosing. After a brief discussion of the pharmacokinetics of milrinone, this article examines milrinone dosing, observed hemodynamic benefits, and documented adverse events across different studies.

Systemic thrombolysis: cure for prosthetic mitral valve thrombosis in the comorbid, non-surgical candidate

Severe haemolytic anaemia is a rare complication of prosthetic valve thrombosis (PVT). Emergent surgical replacement of the affected valve is normally the treatment of choice unless contraindicated, such as in high surgical risk patients. Systemic thrombolysis is the alternative to surgical valve replacement. The purpose of this report is to highlight the unique case of an elderly man with New York Heart Association class IV heart failure, history of extensive cardiopulmonary surgeries and haemorrhagic stroke, who presented with severe haemolytic anaemia secondary to prosthetic mitral valve thrombosis. After weighing the risks and benefits, our decision was to use systemic thrombolytic therapy, even in light of the patients previous intracranial haemorrhage. Pretreatment and post-treatment Doppler echocardiography showed markedly reduced regurgitant jetting that ultimately resolved completely, thereby eliminating the underlying cause of haemolysis and achieving symptom resolution.