Key Clinical Summary: Rethink Pulmonary Arterial Hypertension - Optimize Escalation and Combination Therapy

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Myth 4: Escalation Can Wait Until Patients Worsen

Introduction
This summary examines contemporary evidence and guideline‑directed strategies for timely treatment escalation in pulmonary arterial hypertension (PAH), emphasizing the limitations of waiting for overt clinical deterioration before intensifying therapy. It reviews the role of structured risk assessment, the importance of integrating hemodynamic and imaging data with noninvasive markers, and the need for individualized treatment plans that incorporate pathway‑based rationale and patient‑specific factors. The long‑term outcomes associated with early escalation are highlighted through a clinical case.

Initial Presentation and Diagnostic Evaluation

• A 42‑year‑old woman with rheumatoid arthritis (RA) receiving infliximab therapy presented with exertional dyspnea
• She remained able to perform activities of daily living but experienced symptoms with faster walking or climbing stairs
• Initial workup:
  • Pulmonary function tests near normal
  • No interstitial lung disease on imaging
  • Normal ventilation–perfusion scan
  • Routine laboratory studies unremarkable
• Echocardiography suggested pulmonary hypertension, prompting right‑heart catheterization
• Hemodynamics at diagnosis:
  • Mean pulmonary artery pressure (PAP) 48 mmHg
  • Cardiac index 2.6 L/min/m²
  • Pulmonary vascular resistance (PVR) 8.7 WU
  • Pulmonary artery wedge pressure 5 mmHg
  • Findings consistent with precapillary PAH

Initial Therapy and Early Follow‑Up

• Guideline‑directed initial therapy with dual oral agents: a phosphodiesterase 5 inhibitor and an endothelin receptor antagonist
• At 6 and 12 months, the patient reported subjective improvement
• Objective measures showed mixed progress:
  • Functional class (FC) improved from III to II
  • Six‑minute walk distance (6MWD) increased modestly (386 to 425 m at 6 months) but declined to 391 m at 1 year
  • NT‑proBNP decreased initially (451 to 362 pg/mL) but rose again to 489 pg/mL at 1 year
• Despite partial improvement, these findings did not meet low‑risk thresholds

Risk Stratification and Interpretation Challenges

• Formal risk assessment using European Society of Cardiology/European Respiratory Society (ESC/ERS) 4‑strata and REVEAL Lite 2 placed her in the intermediate–low- or intermediate-risk category
  • ESC/ERS criteria: FC II, 6MWD 320–440 m, NT‑proBNP 300–649 pg/mL
  • REVEAL Lite: additional points for systolic blood pressure <110 mmHg and elevated heart rate
• Important caveats:
  • Younger patients may ‘overperform’ on walk tests despite severe hemodynamics.
  • Comorbidities such as RA or obesity may worsen noninvasive markers independent of PAH severity
• Risk scores alone were insufficient; further evaluation with imaging and repeat catheterization was required to complete the assessment

Echocardiographic Findings and Clinical Implications

• Serial echocardiograms at baseline, 6 months, and 1 year showed a concerning trajectory:
  • Severe right atrial enlargement at all time points
  • Progressive right ventricular dilation
  • Moderate‑to‑severe tricuspid regurgitation, worsening over time
  • Right ventricle (RV) systolic pressure remained markedly elevated (71–95 mmHg)
  • RV function appeared mildly improved, but interpretation was confounded by severe tricuspid regurgitation
• The overall pattern indicated significant right‑sided remodeling, inconsistent with low‑risk status despite modest symptomatic gains

Hemodynamic Reassessment and Worsening Physiology

• Repeat catheterizations revealed minimal improvement in PAPs or PVR at 6 months, marked decline in cardiac index at 1 year (2.6 to 1.7 L/min/m²), rising PVR to 13 WU, and decreasing pulmonary artery oxygen saturation (63 to 50%)
• These findings indicated worsening right‑ventricular output and progression of disease despite dual therapy

Clinical Deterioration and Need for Escalation

• Prior to the 1‑year catheterization, fluid retention occurred, requiring escalating diuretics
• After the hemodynamic decline was documented, treatment options were discussed: either parenteral or inhaled prostacyclin therapy
• Before additional therapy could be initiated, she experienced severe decompensation with tachyarrhythmias and volume overload, resulting in admission to intensive care
• Intravenous (IV) prostacyclin was started urgently

Long‑Term Outcomes Following Escalation

• After initiation of IV prostacyclin, the patient demonstrated substantial improvement: PAPs decreased significantly, PVR fell to <5 WU, and cardiac index normalized
• Echocardiography over 15 years showed a marked reduction in right‑sided chamber size, normalization of RV systolic function, and only mild residual right‑sided dilation
• At age 62, she remained stable (FC II, 6MWD 457 m, NT‑proBNP 248 pg/mL, echocardiogram with normal RV size and function)

Conclusions
This case illustrates the risks of delaying treatment escalation in PAH until overt clinical worsening occurs. Intermediate–low risk is not equivalent to low risk, and noninvasive markers may underestimate disease severity, particularly in younger patients. Comprehensive assessment incorporating imaging and hemodynamics is essential to identify patients who require intensification of therapy. Early escalation, rather than waiting for decompensation, offers the best opportunity to prevent right‑ventricular failure and achieve long‑term stability.

Content is accurate as of the date of release on 13 February 2026.