No “great divide” in patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary endarterectomy?

CTEPH, pulmonary endarterectomy, reference center, sociodemographic disparity

Su et al. assessed retrospectively in the present study the impact of sociodemographic disparities in patients undergoing pulmonary endarterectomy (PEA) in their centre over a 10-year period. A total of 235 patients with chronic thromboembolic pulmonary hypertension (CTEPH) underwent PEA during the observation period, reflecting a program of about 25 PEAs per year. First, the authors and their pulmonary hypertension (PH) team at Columbia have to be congratulated for the good results obtained at their specialized centre. According to the current European guidelines, it is recommended with level C evidence that a referral centre should follow at least 50 patients with pulmonary arterial hypertension (PAH) or CTEPH and should receive at least 2 new referrals per month [1]. The mean pulmonary arterial pressure among their patients is 27 (22.00, 33.00) in women and 28 (24.00, 35.25) in men immediately postoperatively [falling from 43.68 (13.71)] in women and from 43.14 (13.88) in men. Although long-term data are missing, these are indeed good haemodynamic results. In addition, the mortality of 6.3% is comparable to an international in-hospital mortality of 4.7% [1, 2]. These results demonstrate that PEA—even though a highly complex procedure requiring an expert team of surgeons, respirologists, anaesthesiologists, perfusionsts, intensive care unit specialists, radiologists and PH nurses—provides good haemodynamic results in expert centres.

The main finding of the present analysis was that sex and socioeconomic status assessed by zip code-linked Distressed Communities Index and race were not associated with adverse outcomes immediately postoperatively, nor were they associated with the 2-year survival rate.

The fact that no disparities were identified is indeed an extremely positive result as it is a well-known phenomenon reported for other cardiothoracic procedures [3]. In other centres, early mortality was observed to be higher in women undergoing PEA, as reported by a Scandinavian observational cohort study of 444 patients. In contrast, long-term survival analysis suggested, that the observed survival in men was close to the expected survival in the matched general population, whereas survival in women deviated notably from that of the matched general population [4]. This finding is in contrast to the results of an analysis of sex-specific differences in the European CTEPH registry showing that women had better long-term survival, irrespective of the performance of PEA [5]. A retrospective study of 401 consecutive patients undergoing PEA at Toronto General Hospital over 15 years showed that, despite similar preoperative values, women had significantly less improvement in postoperative total pulmonary vascular resistance. Survival at 10 years reached 73% in women and 84% in men, but women had worse functional class values and a higher requirement for PH therapy. Female sex remained an independent factor affecting the need for targeted PH therapy after PEA in a multivariate analysis (hazard ratio 2.03, 95% confidence interval 1.03–3.98, P = 0.04) [6].

The non-difference in sex, race, and socioeconomic status in the present analysis might reflect the careful selection of patients undergoing PEA at Columbia University Medical Center, New York, which is a crucial success factor for a CTEPH program run by an interdisciplinary team of experts [1]. This theory is underlined by the results of a European registry report in which the cohort comprised an adult population diagnosed with PAH (n = 384) or CTEPH (n = 187) alive in 2016 to 2017 from 3 registries: the Swedish PAH registry, the National Board of Health and Welfare and Statistics Sweden [7]. Sex, age, or socioeconomic factors did not affect adherence to oral disease-specific treatment, which again may simply reflect the well selected and carefully followed patients in a highly specialized centre. As Columbia University is located in a highly educated area of the United States, these results may not be generalizable to the whole US population.

These factors may not exist in every region of the world, because in some countries patients do not even have access to a specialized CTEPH program. Access to specialized CTEPH reference centres is an important aspect that is not reflected in the data presented: The number of patients with CTEPH in New York City and the number of those patients referred for treatment and finally undergoing appropriate treatment are not reported. Eventually, we still might find a difference in referal to surgery, even in such a highly specialized centre. In the European CTEPH registry, this phenomenon of sex difference was demonstrated, because women with CTEPH underwent PEA less frequently than men with CTEPH [1]. Therefore, I think it is of great importance to keep on raising awareness of this disease and the excellent outcomes for CTEPH patients if treated appropriately, independent of the sex, race, and socioeconomic factors of our patients!