Long-term follow-up after surgery for chronic thromboembolic pulmonary hypertension

Abstract

Background: Pulmonary endarterectomy (PEA) is the treatment recommended for all operable patients with chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this thesis was to evaluate long-term survival, quality of life (QoL) and functional status in patients with CTEPH who have undergone PEA.

Methods and results: Study I Survival after PEA was compared with that in the Swedish general population. We included all patients who underwent PEA at Karolinska University Hospital between 1997 and 2018 (N=100). Information on expected survival in the general Swedish population matched for age, sex, and year of surgery was obtained from the Human Mortality Database. The 10-year observed, expected, and relative survival rates were, respectively 69% (95% confidence interval [CI], 57–78), 82%, and 84% (95% CI 69–96). Study II Sex-specific survival after PEA for CTEPH was investigated. All patients who underwent PEA at two Scandinavian centres between 1992 and 2020 were included (N=444; 59% male, 41% female). Data on expected survival in the general population matched for age, sex, and year of surgery were obtained from the Human Mortality Database. Propensity scores and weighting were used to account for differences at baseline. Flexible parametric survival models were used. Unadjusted 30-day mortality was 4.2% in men and 9.8% in women (p=0.020). In weighted analyses, long-term survival did not differ significantly between men and women (hazard ratio: 1.36; 95% CI 0.89–2.06). Relative survival at 15 years conditional on 30-day survival was 94% (95% CI 79–107) in men and 75% (95% CI 59–88) in women. Study III The association between residual pulmonary hypertension after PEA and long-term survival was investigated. All patients who underwent PEA at two Scandinavian centres between 1992 and 2020 (N=444) were included. Residual pulmonary hypertension was defined as an early postoperative mean pulmonary artery pressure of ≥30 mmHg. After weighting, there was a significant association between residual pulmonary hypertension and all-cause mortality (hazard ratio 2.49; 95% CI 1.60–3.87), and the absolute survival difference between the groups was -22% (95% CI -32 to -12) at 10 years and -32% (95% CI -47 to -18) at 20 years. Study IV QoL and functional status were investigated in a cross-sectional manner. All patients who underwent PEA for CTEPH at Karolinska University Hospital between 1992 and 2020 were enrolled. Data were obtained from patient charts and national health data registers as well as from RAND-36 questionnaires and telephone interviews. The RAND-36 scores were slightly lower in the patients who underwent PEA for CTEPH than in the Swedish age-matched reference population in all domains except for bodily pain. All patients, in whom Karnofsky Performance Status was assessed (N=42), were able to live at home and care for most of their personal needs and 74% were able to carry on normal activities. The mean postoperative scores measured by the Cambridge Pulmonary Hypertension Outcome Review were low.

Conclusions: Life expectancy following PEA was shorter than that in the general population, but the difference was small. There was a sex-specific difference in the prognosis after PEA in that women had a higher early mortality rate. However, after adjustment for differences in baseline characteristics, there was no significant sex-related difference in long-term survival despite women deviating more from expected survival than men. Patients with early postoperative residual pulmonary hypertension had worse long-term survival after PEA. QoL after PEA was close to that expected in a reference population, and functional status improved slightly when assessed late after PEA. These findings suggest that many patients enjoy satisfactory QoL and high functional status late after PEA.