Short-term Prognostic Factors of Thrombolytic Therapy for Acute Pulmonary Embolism: A Case-control Study

  Objective  This study aimed to identify the possible short-term risk factors associated with the mortality of patients with acute pulmonary embolism after thrombolytic therapy.

  Methods  We retrospectively collected the patients with acute pulmonary embolism who were diagnosed by computed tomography pulmonary angiography (CTPA) or echocardiography (ECHO) and received thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA) in Peking Union Medical College Hospital from January 2014 to November 2017. The collection of clinical data including comorbidities, course of the disease, clinical features, laboratory tests, imaging findings, simplified pulmonary embolism severity index (sPESI), treatment, outcomes, etc. were used to analyze the prognostic factors of disease 7 days, 14 days and 30 days after thrombolytic therapy.

  Results  A total of 23 patients, 5 males and 18 females, were included in the study with an average age of (57.3 ±14.0) years. Sixteen patients survived (69.6%, 16/23) and 7 died (30.4%, 7/23); the 7-day, 14-day and 30-day mortality was 26.1% (6/23), and 30.4%(7/23), 30.4%(7/23), respectively. Compared to the survival group, patients in the death group had higher sPESI3(2, 3)vs 2(1, 2), P=0.008, lower systolic pressure(79.3±25.4)mm Hg vs (108.7±18.1)mm Hg, P=0.005, less platelets(135.1±58.3)×10⁹/L vs (223.2±89.4)×10⁹/L, P=0.012, lower calcium concentration(1.9±0.2)mmol/L vs(2.1±0.2)mmol/L, P=0.030, higher N-terminal pro-B-type natriuretic peptide (NT-proBNP)6372(1637, 17 228)pg/ml vs 1166(343, 1821)pg/ml, P=0.035, and more frequent cardiopulmonary resuscitation (100% vs 12.5%, P=0.000). Survival analysis indicated that patients who had a heart rate>110 beats/min (P=0.012), systolic blood pressure < 90 mm Hg(P=0.000), cardiopulmonary resuscitation(P=0.000), or NT-proBNP >6000 pg/ml (P=0.001) had a lower 14-day survival rate. Factors such as the absence of malignant tumors or chronic cardiopulmonary disease, arterial oxygen saturation ≥ 90%, platelets ≥ 200×10⁹/L, and blood calcium ≥ 2.00 mmol/L made no difference in the improvement of 14-day survival.

  Conclusions  In patients with acute pulmonary embolism after thrombolytic therapy, hypotension, cardiopulmonary resuscitation, elevated heart rate and NT-proBNP may indicate a higher risk of short-term mortality. Whether hypocalcemia and thrombocytopenia can be used as short-term prognostic factors requires further researches.