Incidence and risk factors for cardiovascular events in patients hospitalized with community-acquired pneumonia

Abstract

Objective: To explore the incidence, risk factors of cardiovascular events (CVE) and their impact on 30-day mortality in patients hospitalized with community-acquired pneumonia (CAP). Methods: This is a multicenter, retrospective study. Patients hospitalized with CAP from 5 teaching hospitals in Beijing, Shandong and Yunnan provinces during 1 January 2013 to 31 December 2015 were included and clinical data were retrieved from the Hospital Information System (HIS), and patients were divided into CVE group and non-CVE group. Age, sex, comorbidities, pneumonia severity index(PSI)/CURB-65 score, routine blood test, biochemical examinations, radiological findings on admission and mortality on 30-day after admission were analyzed. The primary endpoint was acute CVE during hospitalization, the secondary endpoint was 30-day death after admission. Multivariate Cox regression analysis was used to explore the risk factors for CVE. Kaplan-Meier survival curve was used to compare the difference on 30-day mortality between CVE patients and non-CVE patients by Log-rank test. Multivariate Cox regression model was used to assess the impact of CVE on the 30-day mortality among CAP patients after adjustment with age, sex, comorbidities, PSI/CURB-65 score. Results: A total of 3 561 CAP patients were included into the final analysis, including 210 (5.9%) patients in CVE group and 3 351 (94.1%) patients in non-CVE group. Compared with patients in non-CVE group, patients in CVE group were older (P<0.001), prevalence of hypertension, coronary heart disease, chronic heart failure, cerebrovascular disease, chronic obstructive pulmonary disease, chronic kidney disease, aspiration risk and bedrid were significantly higher (all P<0.001); prevalence of CURB-65 score 3-5 and PSI risk class Ⅳ/Ⅴ were also significantly higher (both P<0.001). The proportion of axillary temperature<36 ℃, respiratory rate≥30 beats/minutes, confusion, leukocytes>10×10(9)/L, hemoglobin<100 g/L, platelets>300×10(9)/L, albumin<35 g/L, blood urea nitrogen>7 mmol/L, fasting blood glucose>11 mmol/L, serum C-reaction protein>100 mg/L, serum procalcitonin≥2 μg/L, arterial pH<7.35, arterial PO(2)/FiO(2)≤300 mmHg (1 mmHg=0.133 kPa), and multilobar infiltrates and pleural effusion on chest X-ray or CT scan were significantly higher in CVE group than in non-CVE group(all P<0.05); the 30-day mortality was significantly higher in CVE group than in non-CVE group(P<0.001). The incidence of CVE was significantly higher in patients with cardiovascular and cerebrovascular disease(CVD) than in patients without CVD (13.9%(150/1 079) vs. 2.4%(60/2 482), χ(2)=178.737, P<0.001). Meanwhile, the incidence of CVE increased with PSI in patients with Ⅰ/Ⅱ, Ⅲ and Ⅳ/Ⅴ class, respectively(χ(2)=228.350, P<0.001); and CURB-65 score 0-1, 2 and 3-5, respectively (χ(2)=387.154, P<0.001). Cox regression analysis revealed that age (HR=1.05, 95%CI 1.02-1.09, P=0.002), coronary heart disease (HR=1.88, 95%CI 1.01-3.51, P=0.048), chronic heart failure (HR=4.25, 95%CI 1.89-9.52, P<0.001), PSI risk class (HR=1.66, 95%CI 1.50-2.62, P=0.029) and serum procalcitonin≥ 2 μg/L (HR=3.72, 95%CI 1.60-8.66, P=0.002) were independent risk factors for CVE in CAP patients. Kaplan-Meier curve showed that the survival probability of patients with CVE was significantly lower than patients without CVE (P<0.001). After adjustment for age, sex, comorbidities and PSI/CURB-65 score, Cox regression model showed that CVE was associated with increased 30-day mortality in CAP patients (HR=6.05, 95%CI 3.11-11.76, P<0.001). Conclusions: Although the incidence of CVE is not high in Chinese patients hospitalized with CAP, CVE is common in patients with severe pneumonia and in patients with CVD. Age, cardiovascular disease, PSI risk class and serum procalcitonin are the risk factors for CVE in this patient cohort. CVE is related to increased 30-day mortality in CAP patients.