原発性肺高血圧症の血行動態からみた予後

Prognosis of the Primary Pulmonary Hypertension from the Hemodvnamic Point of View

　【背景】原発性肺高血圧症（PPH）に対して約10年前から血管拡張薬療法（VDT）が導入されたが，適応基準は確立されていない．この研究はPPHの自然歴を検討し，VDTの簡便な適応基準を示すことを目的とした．【方法】対象は右心カテーテル検査後の予後が明らかにされた51例．肺循環動態と予後との関係をみた．【結果】2年以内死亡，2年以上生存で区別すると，前者は心係数が低く肺血管抵抗が高かった．心係数を2.4l／min／m²，肺動脈収縮期圧を90mmHgで4象限に区分し，心係数＞2.4，肺動脈収縮期圧＜90 mmHgをsubset I，以下反時計回りにII, III, IVとすると，この順に各subset間で有意差を以て平均生存期間が短縮した．【結論】PPHのVDTに対する簡便な適応基準を示した．VDTはsubset I・IIが良い適応であり，III・IVは慎重に対処すべきである．

Vasodilator therapy was introduced for the treatment of primary pulmonary hypertension (PPH) some 10 years ago. However, inclusion criteria have not yet been determined. This study attempted to clarify the natural history of PPH in terms of pulmonary hemodynamics and to evaluate vasodilator therapy. Subjects were 51 patients with PPH. We divided the patients into 4 groups by cardiac index (CI)=2.4 l/min/m² and systolic pulmonary artery pressure (PA)=90 mmHg. Subset I consisted of patients with CI＞2.4 //min/m² and PA ＜90 mmHg with the other subsets (II～IV) following coun-terclockwise. Every patient in subset I survived 2 years or more. Survival rates greater than 2 years in subsets II to IV were 79, 40, and 25%, respectively. The survival rate determined by the Kaplan-Meier method, from the day after cardiac catheterization showed statistically significant differences between each subset. We conclude that the prognosis of PPH can be determined using our classification. This can also be used to monitor the efficacy of vasodilator therapy.