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Evaluating suspected pulmonary hypertension: A structured approach

Cleveland Clinic Journal of Medicine. 2018 June;85(6):468-480 | 10.3949/ccjm.85a.17065
June 1, 2018|Cleveland Clinic Journal of Medicine
Akshay Bhatnagar, MD;Jonathan Wiesen, MD;Raed Dweik, MD;Neal F. Chaisson, MD
Author and Disclosure Information

Akshay Bhatnagar, MD
Department of Internal Medicine, Cleveland Clinic

Jonathan Wiesen, MD
Community Intensivists, Cleveland, OH; Ben Gurion University, Be’er Sheva, Israel

Raed Dweik, MD
Interim Institute Chair, Respiratory Institute, Cleveland Clinic; Professor, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Neal F. Chaisson, MD
Department of Critical Care Medicine, Respiratory Institute, Cleveland Clinic; Assistant Professor, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH

Address: Neal F. Chaisson, MD, Respiratory Institute, A90, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; chaissn@ccf.org

ABSTRACT

Pulmonary arterial hypertension (PAH) is a common consideration when patients have unexplained signs of cardiopulmonary disease. Guidelines have been issued regarding diagnosis and management of this condition. Since multiple conditions can mimic components of PAH, the clinician should think about the patient’s total clinical condition before diagnosing and categorizing it. Proper evaluation and etiologic definition are crucial to providing the appropriate therapy. This review offers a case-based guide to the evaluation of patients with suspected PAH.

KEY POINTS

  • PAH has nonspecific symptoms, largely attributable to right ventricular dysfunction but seen in a host of other common cardiopulmonary ailments.
  • In a patient suspected of having pulmonary hypertension, it is important to take a methodic diagnostic approach to identify underlying contributors and minimize unnecessary testing.
  • Patients suspected of having PAH should be referred to a pulmonary hypertension center of excellence for evaluation and right heart catheterization.
  • Once testing is complete, therapy and management should be guided both by data obtained during the initial evaluation and by factors with prognostic significance. This approach has changed PAH from a disease with a grim outlook to one in which appropriate evaluation and guidance can improve patient outcomes.

PROGNOSTIC RISK STRATIFICATION IN THE PATIENTS WITH PAH

The final challenge in evaluating patients with suspected PAH is to estimate their risk of death. Although nonmodifiable risk factors including age, sex, and associated comorbidities play a significant role in determining prognosis, several potentially modifiable risk factors should be used to estimate the 1-year mortality risk (Table 3). These include features on physical examination consistent with right heart failure, New York Heart Association functional class, 6-minute walking distance or cardiopulmonary exercise capacity, N-terminal pro-B-type natriuretic peptide (NT-proBNP) level, and findings on echocardiography and right heart catheterization.1

Cardiac magnetic resonance imaging (MRI) has gained popularity as a noninvasive and reproducible alternative to echocardiography. Image fidelity and characterization of right ventricular function and right ventricular ejection fraction are all more accurate than with echocardiography, and serial MRI has proven valuable in its ability to guide patient prognosis.46

However, MRI is more expensive than echocardiography, and some patients cannot tolerate the procedure. In addition, for those who can tolerate it, MRI is not a suitable alternative to right heart catheterization, since it cannot accurately estimate pulmonary artery occlusion pressure or pulmonary arterial pressures.1 For these reasons, cardiac MRI use varies across pulmonary hypertension centers.

A goal of treatment is to reduce a patient’s risk. While no consensus has been achieved over which PAH-specific therapy to start with, evidence is robust that using more than 1 class of agent is beneficial, capitalizing on multiple therapeutic targets.17,47

In our patient, right heart catheterization revealed PAH with a mean pulmonary arterial pressure of 44 mm Hg, pulmonary artery occlusion pressure 6 mm Hg, and a cardiac index of 2.1 L/min/m2. Ancillary testing for alternative causes of PAH was unrevealing, as was vasoreactivity testing. Our patient could walk only 314 meters on her 6-minute walk test and had an initial NT-proBNP level of 750 ng/L.

Based on these and the findings during her evaluation, she would be classified as having intermediate-risk PAH with an estimated 1-year mortality risk of 5% to 10%.1 Appropriate therapy and follow-up would be guided by this determination. Specific therapy is beyond the scope of this article but we would start her on dual oral therapy with close follow-up to reassess her 1-year mortality risk. If there were no improvement over a short period of time, we would add further therapy.

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