Although failure and mortality are the most relevant outcomes in patients with Community-acquired Pneumonia (CAP), there is little discussion in the literature on their incidence and etiology. A pathophysiological approach has been recently developed and used to evaluate clinical failure in CAP patients. Clinical failure has been analyzed as related versus unrelated to CAP, considering the role that the pulmonary infection and the inflammatory response played in the development of this outcome. Cardiac events were identified as triggers of clinical failures in a significant percentage of CAP patients. The development of cardiovascular events have been also identified in CAP patients both on admission to the hospital and during hospitalization. However, data on this topic belong to studies evaluating only selected populations of veteran patients with CAP. Understanding clinical failure, as well as cardiovascular events in hospitalized patients with CAP would be useful in order to prevent complications during the hospitalization, to develop new treatment modalities and, thus, to improve outcomes.

The objectives of this international, multicenter, observational, prospective cohort study will be: 1) To define incidence, timing, etiology and risk factors of clinical failure, related vs. unrelated to CAP, in hospitalized patients with CAP; 2) To define incidence, timing, and risk factors for cardiovascular events either on hospital admission or during hospitalization in hospitalized patients with CAP.Consecutive adult patients hospitalized for CAP in acute care hospitals in Europe and US will be enrolled. Daily clinical evaluations. Demographics, history, clinical, radiological, and antibiotic therapy data will be recorded, as well as serum, urinary and respiratory samples will be collected both on admission and during hospitalization from consenting individuals. Patients will be classified as having a CAP-related versus CAP-unrelated failure, according to a pathophysiological classification. Patients will be also classified as having or not a cardiovascular event either on admission or during hospitalization.The following outcomes will be measured:

1) Incidence, timing, etiology and risk factors of clinical failure related vs. unrelated to CAP; 2) Incidence, timing and risk factors of cardiovascular events; 3)time to clinical stability, length of hospital stay, mortality at hospital discharge, and mortality at 30 and 180 days.

Inclusion Criteria:

1) Signed inform consent to participate in the study

2) Criteria for community-acquired pneumonia:

1. New pulmonary infiltrate seen on chest radiograph or CT Scan of the chest within 48 hours after hospitalization.

   plus at least one of the following:

2. New or increased cough with/without sputum production

3. Fever (documented temperature -rectal or oral- > 38.3 or hypothermia (documented temperature -rectal or oral- < 36 C)

4. Evidence of systemic inflammation (such as abnormal white blood cell count -either leukocytosis (> 10,000/cm3) or leukopenia (< 4,000/cm3) - or C-reactive protein (CRP) or procalcitonin (PCT) values above the local upper limit.

3) Patients with a diagnosis of healthcare-associated pneumonia (HCAP) will be included in the study and a secondary analysis will performed on this subgroup of patients.

Exclusion Criteria:

Patients who meet at least one of the following definitions will be excluded from the analysis:

1. Patient has hospital-acquired pneumonia, defined as pneumonia that develops after 48 hours of the current hospitalization, or pneumonia that develops in a patient who had been discharged from the hospital within the prior 14 days of the current hospitalization.
2. Patient is re-admitted with a new episode of pneumonia during the 14-day follow up period from the previous hospitalization.
3. Unstable psychiatric or psychological condition rendering the subject unlikely to be cooperative or to complete the study requirements.
4. Subject history that in the investigator's opinion would preclude subject compliance with the protocol.

All consecutive patients admitted to any of the study centers will be screened for study entry. Patients with a diagnosis of community-acquired pneumonia (including those with health-care associated pneumonia) will be evaluated to define study entry criteria