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A striking feature of the human pulmonary circulation is that mean (mPAP) and systolic (sPAP) pulmonary artery pressures (PAPs) are strongly related and, thus, are essentially redundant. According to the empirical formula documented under normotensive and hypertensive conditions (mPAP = 0.61 sPAP + 2 mmHg), sPAP matches ~160%mPAP on average. This attests to the high pulsatility of PAP, as also witnessed by the near equality of PA pulse pressure and mPAP. Our prospective study tested if pressure redundancy and high pulsatility also apply in a piglet model of chronic thromboembolic pulmonary hypertension (CTEPH). At baseline (Week‐0, W0), Sham (n = 8) and CTEPH (n = 27) had similar mPAP and stroke volume. At W6, mPAP increased in CTEPH only, with a two‐ to three‐fold increase in PA stiffness and total pulmonary resistance. Seven CTEPH piglets were also studied at W16 at baseline, after volume loading, and after acute pulmonary embolism associated with dobutamine infusion. There was a strong linear relationship between sPAP and mPAP (1) at W0 and W6 (n = 70 data points, r² = 0.95); (2) in the subgroup studied at W16 (n = 21, r² = 0.97); and (3) when all data were pooled (n = 91, r² = 0.97, sPAP range 9–112 mmHg). The PA pulsatility was lower than that expected based on observations in humans: sPAP matched ~120%mPAP only and PA pulse pressure was markedly lower than mPAP. In conclusion, the redundancy between mPAP and sPAP seems a characteristic of the pulmonary circulation independent of the species. However, it is suggested that the sPAP thresholds used to define PH in animals are species‐ and/or model‐dependent and thus must be validated. [ABSTRACT FROM AUTHOR]

Background: Our aim was to describe the results of our program of surgical resection of tumors invading the inferior vena cava (IVC) at the hepatic and thoracic levels. We hypothesized that similar surgical outcomes may be obtained compared to tumor resection below the hepatic vein level if the liver function was preserved. Methods: We performed a single-center retrospective study of 72 consecutive patients who underwent surgical resection from 1996 to 2019 for tumors invading the IVC. We compared two groups based on tumor location below (group I/II) or above (group III/IV) the inferior limit of hepatic veins. Results: Tumor histology was similarly distributed between groups. In group III/IV (n = 35), sterno-laparotomy was used in 83% of patients, cardiopulmonary bypass in 77%, and deep hypothermic circulatory arrest in 17%; 23% underwent liver resection. Corresponding proportions in group I/II were 3%, 0%, 0%, and 8%. In group III/IV, 4 patients required emergency resection. Mortality on day 30 was 17% (n = 6) in group III/IV and 0% in group I/II (P = 0.01). There was no liver failure among the 66 postoperative survivors and 5 out of 6 patients who died postoperatively presented a preoperative or postoperative liver failure (P < 0.001). Overall survival was not significantly different between groups with a median follow-up of 15.1 months. R0 resection was achieved in 66% of group I/II and 49% of group III/IV patients (P = 0.03). Conclusion: Surgical resection of tumors invading the inferior vena cava at hepatic vein and thoracic levels should be reserved to carefully selected patients without preoperative liver failure to minimize postoperative mortality. [ABSTRACT FROM AUTHOR]

Patients with idiopathic pulmonary arterial hypertension (IPAH) have improved survival after heart-lung transplantation (HLT) and double-lung transplantation (DLT). However, the optimal procedure for patients with IP AH undergoing transplantation remains unclear. We hypothesized that critically ill IP AH patients, defined by admission to the intensive care units (ICU), would demonstrate improved survival with HLT vs. DLT. All adult IP AH patients (>18 yr) in the Scientific Registry of Transplant Recipients (SRTR) database, who underwent either HLT or DLT between 1987 and 2012, were included. Baseline characteristics, survival, and adjusted survival were compared between the HLT and DLT groups. Similar analyses were performed for the subgroups as defined by the recipients' hospitalization status. A total of 928 IP AH patients (667 DLT, 261 HLT) were included in this analysis. The HLT recipients were younger, more likely to be admitted to the ICU, and have had their transplant in previous eras. Overall, the adjusted survivals after HLT or DLT were similar. For recipients who were hospitalized in the ICU, DLT was associated with worse outcomes (HR 1.827; 95% CI 1.018-3.279). In IP AH patients, the overall survival after HLT or DLT is comparable. HLT may provide improved outcomes in critically ill IP AH patients admitted to the ICU at time of transplantation. [ABSTRACT FROM AUTHOR]

Background: Tricuspid annular systolic excursion (TAPSE) or velocities (s′) and right ventricular (RV) end‐systolic dimensions are predictors of outcome in patients with pulmonary hypertension (PH). We explored the value of combining peak s′ and RV end‐systolic area index (RVESAi) as a surrogate of RV‐pulmonary artery (RV–PA) coupling in a large animal of precapillary PH as well as clinically. Method: The first experimental group included four control and four piglets with thromboembolic disease. RV–PA coupling was assessed by ventricular to arterial elastance ratio (Ees/Ea) at baseline, after esmolol and dobutamine administration. Echocardiographic metrics included s′, TAPSE, fractional area change (RVFAC), and RVESAi. The findings were validated in six piglets with severe PH. Clinical cohorts were stable outpatients (n = 141) and acutely decompensated pulmonary arterial hypertension (n = 48). Results: In the first experimental group, the best linear correlates of Ees/Ea were s′ (R2 =.51, p <.001) and RVESAi (R2 =.50, p <.001), while RVFAC (R2 =.17, p =.01) and TAPSE showed weaker association (R2 =.21, p =.39). The ratio s′/RVESAi showed nominally but not significantly (higher) association with Ees/Ea (R2 =.58, p <.01). The association between changes in s′/RVESAi and Ees/Ea was strong (R2 =.56, p <.001). In more severe PH, Ees/Ea and changes in Ees/Ea correlated significantly with s′/RVESAi and changes in s′/RVESAi (R2 =.69; p <.001 and R2 =.64, p <.001, respectively). In the two clinical cohorts, the s′/RVESAi did not emerge as a stronger predictor of outcome than RVESAi. Conclusion: RV s′/RVESAi index represents a reasonable bedside‐usable surrogate of RV–PA coupling and of its acute variations in PH. Its incremental prognostic value over end‐systolic dimension alone remains to be proven. [ABSTRACT FROM AUTHOR]