Pulmonary Artery Pulsatility Index (PAPi)

• Interpret results in the context of the overall clinical picture and other measures of right ventricular function. 
• Avoid applying fixed cutoff values, as thresholds may vary across patient populations, clinical settings, age groups, and sexes, and population-specific differences are not well defined.
• Clinical interpretation should be individualized, as optimal thresholds vary across cardiogenic shock, advanced heart failure, pulmonary hypertension, and mechanical circulatory support populations. 
• Where possible, interpret results within population-specific frameworks (e.g., cardiogenic shock, LVAD evaluation, pulmonary hypertension), as risk gradients differ across these groups.
• Consider repeating measurements when clinical status changes or during treatment monitoring.

PAPi thresholds are population- and context-dependent; the following ranges are approximate and should not be applied universally:

• <1.0:
  
  • Consistently associated with severe right ventricular dysfunction and high risk of adverse outcomes across multiple populations.
  • Consider urgent evaluation for therapy escalation, including inotropes, pulmonary vasodilators, or mechanical circulatory support when clinically appropriate.
• 1.0–2.0:
  
  • Suggests possible right ventricular dysfunction, though risk varies by clinical context.
  • Consider closer monitoring and optimization of preload, afterload, and right ventricular contractility.
• >2.0: 
  
  • Generally associated with lower risk of severe right ventricular failure in some populations, but does not exclude adverse outcomes.
  • Higher thresholds (e.g., >3–5) have been associated with lower risk in certain cohorts; interpret in the context of the underlying disease state.

• Assess for clinical and hemodynamic evidence of right ventricular failure and optimize preload, afterload, and contractility as appropriate. 
• Consider early consultation with advanced heart failure or cardiogenic shock teams when results suggest high risk. 
• Reassess hemodynamics and escalate therapies, including mechanical circulatory support, when clinically indicated.