Mild vs severe pulmonary hypertension before heart transplantation: different effects on posttransplantation pulmonary hypertension and mortality. 
Pulmonary hypertension (PH) is common in severe heart failure, but the effect of mild PH on posttransplantation PH and survival after heart transplantation has not been well described.  This cohort study examined preoperative and postoperative hemodynamics in 172 heart transplant recipients at Johns Hopkins Hospital followed for up to 15.1 years.  PH was defined as pulmonary vascular resistance > or =2.5 Wood units, as measured during routine right heat catheterization; mild to moderate PH was defined as PVR between 2.5 and 4.9 Wood units; and severe PH was defined as PVR > or =5.0 Wood units.  Seventy-one patients (41.3%) had PH, mostly of mild/moderate severity (77.5%), at the last routine hemodynamic monitoring before transplantation (median time before transplantation, 2.7 months).  During follow-up, 105 patients (62.9%) developed PH at some point after transplantation, and 48 patients died (cumulative incidence, 76.5%).  Mild/moderate preoperative PH was associated with increased risk of posttransplantation PH at 1, 3, and 6 months, but not with later episodes of PH.  Mild/moderate preoperative PH was not associated with a higher mortality rate, but each 1 Wood unit increase in preoperative PVR demonstrated a trend toward increased mortality.  Severe preoperative PH was associated with death within the first year after adjusting for potential confounders, but not with overall mortality or mortality at other time points.  Mild to moderate preoperative PH is associated with increased risk of developing early but not late posttransplantation PH and may suggest different management strategies.  Although PH was not consistently associated with mortality, increasing severity of the preoperative PH suggests potentially worse prognosis.