Frantz, Robert P.

Background Diastolic pulmonary gradient ( DPG ) was proposed as a better marker of pulmonary vascular remodeling compared with pulmonary vascular resistance ( PVR ) and transpulmonary gradient ( TPG ). The prognostic significance of DPG in patients requiring a left ventricular assist device ( LVAD ) remains unclear. We sought to investigate whether pre‐ LVAD DPG is a predictor of survival or right ventricular ( RV ) failure post‐ LVAD . Methods and Results We retrospectively reviewed 268 patients who underwent right heart catheterization before LVAD implantation from 2007 to 2017 and had pulmonary hypertension because of left heart disease. Patients were dichotomized using DPG ≥7 mm Hg, PVR ≥3 mm Hg, or TPG ≥12 mm Hg. The associations between these parameters and all‐cause mortality or RV failure post LVAD were assessed with Cox proportional hazards regression and Kaplan–Meier analyses. After a mean follow‐up time of 35 months, elevated DPG was associated with increased risk of RV failure (hazard ratio [ HR ]: 3.30; P =0.004, for DPG ≥7 versus DPG <7), whereas elevated PVR ( HR 1.85, P =0.13 for PVR ≥3 versus PVR <3) or TPG ( HR 1.47, P =0.35, for TPG ≥12 versus TPG <12) were not associated with the development of RV failure. Elevated DPG was not associated with mortality risk ( HR 1.16, P =0.54, for DPG ≥7 versus DPG <7), whereas elevated PVR , but not TPG , was associated with higher mortality risk ( HR 1.55; P =0.026, for PVR ≥3 versus PVR <3). Conclusions Among patients with pulmonary hypertension because of left heart disease requiring LVAD support, elevated DPG was associated with RV failure but not survival, while elevated PVR predicted mortality post LVAD implantation.

Pulmonary arterial hypertension (PAH) is a rare disease that carries a poor prognosis. For 45 years, the definition of pulmonary hypertension (PH) has been a mean pulmonary arterial pressure (mPAP) ≥ 25 mmHg, based on expert opinion. Recent data indicate that the mortality risk starts in the mPAP range of 21–24 mmHg, which has recently been reflected in the World Symposium on PH consensus document defining PH as a mPAP > 20 mmHg. The mortality associated with these lower levels of pulmonary pressures suggests that these values reflect a more advanced disease stage than previously recognized. It is unknown whether interventions targeting patients with mPAP values in the range of 21–24 mmHg in the absence of left ventricular or hypoxic lung disease are of clinical benefit. Here we present historical perspective on the hemodynamic definition of PH, discuss recent epidemiologic data, and outline obstacles to enrolling and evaluating response to therapy in mild PAH patients, as well as potentially useful study designs.

Section editor's note: Welcome to a new section in Advances titled “Pulmonary Hypertension Grand Rounds” (PHGR), which we are introducing in this issue. With this addition, Advances offers a unique opportunity for trainees and junior faculty interested in pulmonary hypertension (PH). This section will highlight cases with literature reviews written by young clinicians and researchers in PH. PHGR was created to use patient cases to integrate individual clinical expertise with the best available evidence from the literature to enable the best decisions for patients. As with the rest of the journal, our audience continues to be physicians, researchers, nurses, students, residents, and fellows interested in both the care of individual patients and the advances in our field. We welcome comments about the section and inquiries regarding submitting a case for publication. Please direct inquiries to advancesgrandrounds@PHAssociation.org

Abstract Abstract Background: Pulmonary hypertension (PH) is a significant preoperative risk factor. We aimed to determine predictors of perioperative morbidity and mortality after noncardiac surgery for patients with precapillary PH. Methods: We conducted a retrospective cohort study of adults with pulmonary hypertension having surgery at a single large medical referral center. The PH and surgical databases were reviewed from 2010 to 2017. Patients were excluded if PH was attributable to left-sided heart disease or they had undergone cardiac or transplant operations. To assess whether PH-specific diagnostic or cardiopulmonary testing parameters were predictive of perioperative complications, analyses were performed using generalized estimating equations. Results: Of 196 patients with PH undergoing noncardiac operations, 53 (27%) experienced 1 or more complications, including 5 deaths (3%) within 30 days. After adjustment for age and PH type, there were more complications in those undergoing moderate-to-high vs low-risk procedures (odds ratio [OR], 4.17 [95% CI, 2.07 to 8.40]; P<0.001). After adjustment for age, surgical risk, and PH type, the risk for complications was higher for patients with worse functional status (OR, 2.39 [95% CI, 1.19 to 4.78]; P=0.01 for class 3/4 vs class 1/2) and elevated serum N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) (OR, 2.28 [95% CI, 1.05 to 4.96]; P=0.04 for ≥300 vs. <300 pg/mL). From an analysis that included covariates for age, surgical risk, and functional status, elevated serum NT-proBNP levels remained associated with increased risk (OR, 2.23 [95% CI, 1.05 to 4.76]; P=0.04). Conclusions: Patients with PH undergoing noncardiac surgery with general anesthesia have a high frequency of perioperative complications. Specific clinical (functional status), diagnostic (serum NT-proBNP), and intraoperative factors (higher-risk surgery) are predictive of worse outcomes.

Background Left ventricular (LV) hemodynamic assessment has been sparsely performed in patients supported on continuous‐flow LV assist devices (cf LVADs ). Insight into dynamic changes of left heart parameters during ramp studies may improve LV assist device optimization and evaluate pathology. Methods and Results To complement right heart catheterization, a novel technique for left heart catheterization in patients with a cf LVAD was developed. Patients implanted with cf LVAD s underwent hemodynamic ramp left heart catheterization and right heart catheterization with transthoracic echocardiography. Continuous aortic and LV pressures were measured along with right atrial, pulmonary artery, and pulmonary capillary wedge pressures. A novel index, the transaortic gradient ( TAG ) was established. Thirty eight patients with cf LVADs were evaluated at a median of 446 days (interquartile range, 183–742) after device implant. During left heart catheterization performed for hemodynamic optimization, drop‐in LV end‐diastolic pressure and pulmonary capillary wedge pressure were associated with a rise in TAG . A range was identified for TAG (20–40 mm Hg) as providing the most optimal level of hemodynamic offloading. Pathologic states deviated from normal responses to ramp. LV assist device thrombosis was associated with an inability to increase in TAG during speed ramp. Significant aortic insufficiency was associated with a marked increase in LV end‐diastolic pressure despite a concomitant decrease in pulmonary capillary wedge pressure with increasing LV assist device speeds. Conclusions Inclusion of left heart catheterization to a typical right heart catheterization LV assist device ramp protocol imparted unique insights to optimize cf LVAD speeds in different clinical scenarios. A novel index, the TAG was defined and provided additional resolution to optimized offloading.

The process of considering initial treatment options for a patient with pulmonary arterial hypertension (PAH), implementing that treatment, and reassessing response can be conceived as a 7-step process. A patient-centered approach, conducted in the context of a pulmonary hypertension care team, implements these steps in a thoughtful and well-organized fashion.Step 1: Perform a thorough diagnostic evaluationStep 2: Consider patient PAH classification and comorbiditiesStep 3: Assess risk profileStep 4: Develop a nuanced understanding of patient goals and preferencesStep 5: Create an initial treatment strategyStep 6: Implement a proactive longitudinal follow-up care planStep 7: Adjust treatment approach based on clear metrics of effectiveness and tolerability The burgeoning array of treatment options for PAH provides the opportunity to tailor therapy to the needs of individual patients, but also demands that the clinician develop a cogent strategy for initiating therapy, monitoring therapeutic response, and addressing side effects of therapy. In this review, we seek to provide a practical framework for approaching this challenge.

Background: We hypothesized that pulmonary venous hypertension in heart failure (HF) leads to predominate remodeling of pulmonary veins and that the severity of venous remodeling is associated with the severity of pulmonary hypertension (PH) in HF. Methods: Patients with HF (n=108; 53 preserved and 55 reduced ejection fraction) with PH (HF-PH; pulmonary artery systolic pressure [PASP] ≥40 mm Hg) were compared to normal controls (n=12) and patients with primary pulmonary veno-occlusive disease (PVOD; n=17). In lung specimens from autopsy (control, HF-PH, and 7 PVOD) or surgery (10 PVOD), quantitative histomorphometry was performed in all analyzable arteries (n=4949), veins (n=7630), and small indeterminate vessels (IV; n=2168) to define percent medial thickness (arteries) and percent intimal thickness (%IT) (arteries, veins, and IV) relative to external diameter. Results: The average arterial percent medial thickness (control, 6.9; HF-PH, 11.0; PVOD, 15.0), arterial %IT (control, 4.9; HF-PH, 14.9; PVOD, 31.1), venous %IT (control, 14.0; HF-PH, 24.9; PVOD, 43.9), and IV %IT (control, 10.6; HF-PH, 25.8; PVOD, 50.0) in HF-PH were higher than controls ( P <0.0001 for all) but lower than PVOD ( P ≤0.005 for all). PASP (mm Hg) was lower in HF-PH (median, 59 [interquartile range, 50–70]) than in PVOD (median, 91 [interquartile range, 82–103]). PASP correlated with arterial percent medial thickness ( r =0.41) and arterial %IT ( r =0.35) but more strongly with venous %IT ( r =0.49) and IV %IT ( r =0.55) ( P <0.0001 for all). Associations between PASP and venous or IV %IT remained significant after adjusting for arterial percent medial thickness and %IT and did not vary by HF type. In patients with right heart catheterization (30 HF-PH, 14 PVOD), similar associations between the transpulmonary gradient and pulmonary vascular remodeling existed, with numerically stronger associations for venous and IV %IT. Although the PASP was slightly higher in patients with HF-PH with right ventricular dysfunction, pulmonary vascular remodeling was not more severe. Pulmonary vascular remodeling severity was associated with reductions in the diffusing capacity of the lungs. Conclusions: In HF, PH is associated with global pulmonary vascular remodeling, but the severity of PH correlates most strongly with venous and small IV intimal thickening, similar to the pattern observed in PVOD. These findings expand our understanding of the pathobiology of PH in HF.