Long-Term Survival In Elderly Patients With Community-Acquired Pneumonia And The Value Of D-Dimer In Predicting It

BackgroundLong recognized as a major cause of death, community-acquired pneumonia(CAP) has been studied intensively in recent years. Despite the research and the development of antimicrobial agents, CAP remains a major cause of death in elderly world-wide. Although studies have assessed short-term mortality among patients with CAP, there is limited data on long-term mortality.Severity assessment is an important component of the management of CAP. The use of a biomarkers could aid in clinical decisions, including illness severity and prognosis assessment. Whether D-dimer level can be used as indicator of prognosis in patients with CAP, is not known.The goals of this study were to(1) explore the survival of CAP with long-term follow-up in elderly,(2) assess the use of D-dimer levels and its association with severity assessment and clinical outcome in elderly hospitalized with CAP.PartⅠ Two-year survival after hospitalization with community-acquired pneumonia in elderly patientsObjective To investigate the two-year survival after hospitalization for community-acquired pneumonia(CAP) in elderly patients. Methods From January 2010 to December 2010, a total of 792 inpatients were enrolled. They were assigned into two groups: CAP group(n=268), were patients hospitalized with a diagnosis of CAP; and control group(n=524), were patients hospitalized for medical conditions other than CAP. The follow-up time was 2 years. Results 116 died by the end of follow-up period(52 in the CAP group and 64 in the control). Kaplan-Meier survival curve showed that the 2-year survival rate of the CAP group was lower than the control group(c2=7.686,P=0.006). In the CAP group, 2-year survival rate of the high-risk patients(Pneumonia Severity Index level: 4~5) was lower than the low-risk patients(level:1~3)(c2=27.126,P<0.001). Patients in the CAP group are more likely died of cardiovascular events than the control group(51.9% vs. 29.7%, P=0.015). Conclusion There is a decreased two-year survival among hospitalized patients with CAP in elderly patients. Cardiac complications are common in these patients and are associated with increased long term mortality, and those patients might need closer follow-up due to their elevated risk of cardiovascular events.PartⅡ The value of D-dimer in predicting short and long term prognosis of elderly patients with community-acquired pneumoniaObjective To evaluate the value of D-dimer in predicting short and long term prognosis of elderly patients with community-acquired pneumonia( CAP).Methods From January 2011 to June 2011, a total of 217 elderly inpatients with CAP were enrolled. After admission, blood samples were obtained for D-dimer, Procalcitonin and C-reactive protein measurement and pneumonia severity index(PSI) was calculated. Clinical and laboratory variables and 30-day mortality were recorded. ROC curves for predicting 30-day mortality were calculated. The survived patients entered 2-year following-up period. They were assigned into two groups according to their D-dimer levels: high D-dimer levels group(D-dimer levels≥500 μg/L)and normal D-dimer levels group(D-dimer levels<500 μg/L). A Kaplan-Meier survive curve was constructed to assess the 2-year survive, and multivariate Cox regression analysis were used to assess the value of D-dimer for predicting long-term prognosis. Results D-dimer levels increased with increasing PSI class: class I~III:288.95(138.55,436.87) μg/L,class IV:550.20(437.65,672.30) μg/L,class V:728.35(558.70,867.50) μg/L(c2=113.93,P<0.001). A significant relationship was found between D-dimer levels and the PSI score(r=0.612,P<0.001). The D-dimer predictive value for 30-day mortality showed an AUC of 0.785(95%CI:0.725-0.838),which was similar with the PSI score(0.828,95%CI:0.771-0.876,P=0.467). The Kaplan-Meier survival curve showed that 2-year mortality rate of high D-dimer levels group was higher than normal D-dimer levels group(c2=20.712,P<0.001).The multivariate logistic regression analysis showed an independent relationship between higher D-dimer levels and long-term mortality(OR=2.05,95%CI:1.48-2.61,P<0.01). Conclusion D-dimer levels could be useful for predicting short and long term prognosis of elderly patients with CAP.