Data on the incidence, associated factors, and prognosis of pericardial effusion (PE) in patients with infective endocarditis (IE) are scarce. Patients with native valve IE were prospectively followed in our center from 1990 to 2007. A logistic regression analysis was performed to identify independent variables associated with PE and mortality. We included 479 episodes of IE from 459 patients (70% men, mean age 51 years). Small-to-moderate PE was observed in 109 episodes (23%) and large-to-very large PE was observed in 9 episodes (2%). Patients with small-to-moderate PE had a greater prevalence of intravenous drug use (38% vs 23%) and more frequent right-sided IE than patients without PE (33% vs 17%). Patients with large-to-very large PE had a higher rate of systemic emboli (22% vs 18%) and periannular abscess (22% vs 6%) than patients without PE. Renal failure was associated with a higher risk of PE (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3 to 3.3); age was associated with a lower risk of PE (OR 0.98, 95% CI 0.97 to 0.99). One-year mortality of patients with IE with large-to-very large PE was higher than that of patients with small-to-moderate and absence of PE (56%, 18%, and 24%, respectively, p = 0.033). Large-to-very large PE increases the 1-year mortality of IE (OR 3.0, 95% CI 1.2 to 7.9). In conclusion, renal failure and younger age are associated with a higher risk of PE. Large-to-very large PE was associated with an increase in 1-year mortality.
The prevalence of pericardial involvement in clinical series of infective endocarditis (IE) is approximately 8.5% ; even higher rates, up to 18% to 20%, have been reported in pathologic studies. Using echocardiography, Reid et al found a 54% prevalence of pericardial effusion (PE) in patients with IE. However, pericardial tamponade and purulent pericarditis are rare complications of IE. In the setting of IE, inflammatory response, heart failure, periannular complications, or infection itself can cause PE, which could be a sign of more severe endocarditis. We studied the incidence of PE and analyzed the risk factors for developing PE. We also assessed the impact of PE on immediate and 1-year outcome of patients with IE.
Methods
We conducted a prospective cohort study at an 850-bed urban tertiary care hospital from January 1990 to December 2007. All consecutive patients with native valve IE were prospectively collected in a specific database. Only patients with a confirmed diagnosis of IE were included in the study. All survivors were followed for at least 1 year. We excluded patients for whom echocardiographic data were not available.
The variables analyzed were demographic data, predisposing conditions, underlying diseases, location of endocarditis, valve affected, microbiologic results, and disease complications.
Diagnosis of IE was made according to the modified Duke criteria. PE was defined as separation of pericardial layers in 2-dimensional transthoracic echocardiography and/or transesophageal echocardiography and was further categorized as small-to-moderate (<10 to 20 mm) or large-to-very large (>20 mm or hemodynamic compromise) following the European Society of Cardiology guidelines. Heart failure was diagnosed by the clinical care team and categorized according to the Killip-Kimball classification. Periannular abscess was defined as abnormal echocardiographically dense or lucent areas within the valvular annulus or perivalvular tissue that was confirmed by imaging in >1 echocardiographic plane.
Echocardiographic studies were performed using a commercially available system within the first 3 days of admission. All echocardiograms were reviewed by the same investigators (MA and JCP). All patients underwent 2-dimensional transthoracic echocardiography and/or transesophageal echocardiography.
Follow-up was at a specific outpatient clinic according to protocol. One-year outcome was recorded by the investigators.
Continuous baseline variables are expressed as mean ± SD. Categorical variables are expressed as a whole number and percentage and compared between groups using the chi-square or Fisher’s exact test when necessary. Logistic regression analysis was performed using a likelihood ratio–based backward exclusion method to evaluate the effect of explanatory variables on mortality or the presence of PE. The variables included in the final adjusted regression model were selected on the basis of a combination of statistical significance (p <0.10) and clinical judgment. The impact of PE at the time of diagnosis of IE on 1-year mortality was evaluated with Kaplan-Meier curves. Survival of patients with large-to-very large PE and patients with small-to-moderate and absence of PE was compared using the log-rank test. For all tests, statistical significance was set at p <0.05. All statistical analyses were performed with SPSS version 18.0 (SPSS Inc., Chicago, Illinois).
Results
We included 479 episodes of IE in 459 patients during the study period ( Figure 1 ). The main characteristics according to the absence of PE, presence of small-to-moderate PE, or large-to-very large PE are listed in Table 1 . The analysis of risk factors associated with PE is listed in Table 2 . Presence of acute renal failure as a complication of IE was associated with PE (odds ratio 2.1, 95% confidence interval 1.3 to 3.3).
| Variable | No PE (n = 361) | Small-to-Moderate PE (n = 109) | Large-to-Very Large PE (n = 9) | p |
|---|---|---|---|---|
| Age (yrs) | 57.0 (37.5) | 47.2 (20.3) | 52.7 (22.0) | 0.033 |
| Men | 253 (70) | 83 (77) | 4 (50) | 0.166 |
| Diabetes mellitus | 35 (10) | 6 (5) | 0 | 0.254 |
| Chronic renal failure or hemodialysis | 30 (8) | 5 (5) | 2 (22) | 0.115 |
| History of cancer | 26 (7) | 9 (8) | 1 (11) | 0.859 |
| HIV infection | 64 (18) | 23 (21) | 2 (22) | 0.701 |
| Chronic liver disease | 43 (12) | 6 (5) | 2 (22) | 0.086 |
| Chronic lung disease | 13 (4) | 3 (3) | 0 | 0.777 |
| Solid organ transplantation | 6 (2) | 1 (1) | 0 | 0.795 |
| IDU | 82 (23) | 42 (38) | 3 (33) | 0.004 |
| Microorganism responsible | ||||
| S aureus | 119 (33) | 45 (41) | 5 (56) | 0.317 |
| Viridans group streptococci + Streptococcus bovis | 105 (29) | 22 (20) | 1 (11) | |
| Coagulase-negative staphylococci | 27 (7) | 13 (12) | 1 (11) | |
| Enterococci | 31 (9) | 9 (8) | 0 | |
| Other | 79 (21) | 20 (18) | 2 (22) | |
| Location | ||||
| Right side | 61 (17) | 36 (33) | 2 (22) | 0.019 |
| Left side | 286 (79) | 72 (66) | 7 (78) | |
| Both | 10 (3) | 1 (1) | 0 | |
| Unknown | 4 (1) | 0 | 0 | |
| Valve affected | ||||
| Aortic | 132 (38) | 37 (35) | 3 (33) | 0.011 |
| Mitral | 124 (36) | 26 (24) | 4 (44) | |
| Tricuspid | 54 (15) | 34 (32) | 2 (22) | |
| >1 Valve | 38 (11) | 9 (8) | 0 | |
| Complications | ||||
| Periannular abscess | 21 (6) | 9 (8) | 2 (22) | 0.113 |
| Heart failure | 161 (45) | 45 (41) | 2 (22) | 0.358 |
| Renal failure | 102 (28) | 45 (41) | 3 (33) | 0.036 |
| Systemic emboli | 66 (18) | 18 (16) | 2 (22) | 0.864 |
| Echocardiographic evaluation | ||||
| Valve perforation or severe regurgitation | 194 (53.7) | 67 (61.5) | 7 (77.8) | 0.149 |
| Vegetation size (mm) | 8.3 (8.9) | 10.1 (8.9) | 5.4 (8.7) | 0.098 |
| Outcome | ||||
| Surgery | 144 (40) | 47 (43) | 4 (44) | 0.813 |
| In-hospital mortality | 71 (20) | 17 (16) | 4 (44) | 0.097 |
| 1-yr mortality | 87 (24) | 20 (18) | 5 (56) | 0.033 |
| Variable | Univariate Analysis | Multivariate Analysis | |||
|---|---|---|---|---|---|
| PE (n = 118) | No PE (n = 361) | p | OR (95% CI) | p | |
| Age (yrs) | 47.6 (20.4) | 57.0 (37.5) | 0.010 | 0.98 (0.97–0.99) | <0.001 |
| Men | 87 (75) | 253 (70) | 0.328 | — | — |
| Diabetes mellitus | 6 (5) | 35 (9.7) | 0.120 | — | — |
| Chronic renal failure or hemodialysis | 7 (6) | 30 (8) | 0.410 | — | — |
| History of cancer | 10 (8) | 26 (7) | 0.649 | — | — |
| Chronic liver disease | 8 (7) | 43 (12) | 0.117 | — | — |
| Chronic lung disease | 3 (2) | 13 (4) | 0.578 | — | — |
| Solid organ transplantation | 1 (1) | 6 (2) | 0.522 | — | — |
| IDU | 45 (38) | 82 (23) | 0.001 | — | — |
| Echocardiographic evaluation | |||||
| Valve perforation or severe regurgitation | 194 (53.7) | 74 (62.7) | 0.088 | — | — |
| Vegetation size (mm) | 9.7 (8.0) | 8.3 (8.9) | 0.129 | — | — |
| Microorganism responsible | |||||
| S aureus | 52 (42) | 124 (34) | 0.116 | — | — |
| Complications | |||||
| Periannular abscess | 11 (9) | 21 (6) | 0.186 | — | — |
| Heart failure | 47 (40) | 161 (45) | 0.364 | — | — |
| Renal failure | 48 (41) | 102 (28) | 0.012 | 2.1 (1.3–3.3) | 0.002 |
| Systemic emboli | 20 (17) | 66 (18) | 0.743 | — | — |
In-hospital mortality of IE with large-to-very large PE was higher than that of IE with small-to-moderate and absence of PE, although the difference was not statistically significant (44%, 16%, and 20%, respectively, p = 0.097). One-year mortality of IE with large-to-very large PE was also higher than that of IE with small-to-moderate and absence of PE (56%, 18%, and 24%, respectively, p = 0.033; Figure 2 ). After controlling for confounders, the presence of large-to-very large PE increased mortality (odds ratio 2.7, 95% confidence interval 1.1 to 7.1). Table 3 lists the analysis of risk factors associated with 1-year mortality.
| Variable | Univariate Analysis | Multivariate Analysis | |||
|---|---|---|---|---|---|
| Death (n = 112) | Survivors (n = 367) | p | OR (95% CI) | p | |
| Age (yrs) | 61.8 (16.4) | 52.5 (437.9) | 0.012 | — | — |
| Men | 84 (76) | 256 (70) | 0.258 | — | — |
| Diabetes mellitus | 12 (11) | 29 (8) | 0.352 | — | — |
| Liver cirrhosis | 20 (18) | 31 (8) | 0.005 | 2.3 (1.3–3.8) | 0.002 |
| Chronic renal failure/hemodialysis | 16 (14) | 21 (6) | 0.003 | — | — |
| Malignancy | 15 (13) | 21 (6) | 0.007 | — | — |
| Chronic pulmonary disease | 5 (4) | 11 (3) | 0.449 | — | — |
| Solid organ transplantation | 3 (3) | 4 (1) | 0.220 | — | — |
| HIV infection | 8 (7) | 81 (22) | <0.001 | 0.6 (0.2–1.8) | 0.430 |
| IDU | 12 (11) | 115 (31) | <0.001 | 0.4 (0.2–0.8) | 0.009 |
| Microorganism responsible | |||||
| S aureus | 46 (41) | 123 (33) | 0.101 | 1.5 (1.0–2.2) | 0.047 |
| Surgical treatment | 47 (42) | 145 (40) | 0.643 | 0.5 (0.3–0.8) | 0.009 |
| Complications | |||||
| Abscess | 14 (12) | 18 (5) | 0.005 | 2.7 (1.4–5.1) | 0.003 |
| Systemic emboli | 29 (26) | 57 (15) | 0.012 | — | — |
| Renal failure | 62 (55) | 88 (24) | <0.001 | 2.6 (1.8–3.9) | <0.001 |
| Heart failure | 75 (67) | 133 (36) | <0.001 | 2.4 (1.5–3.8) | <0.001 |
| Echocardiographic evaluation | |||||
| Valve perforation or severe regurgitation | 189 (51.5) | 79 (70.5) | <0.001 | 1.5 (0.97–2.4) | 0.069 |
| Vegetation size (mm) | 9.4 (9.2) | 8.4 (8.5) | 0.273 | — | — |
| PE | 0.033 | ||||
| No effusion | 87 (77) | 274 (75) | — | — | |
| Small-to-moderate | 20 (18) | 89 (24) | — | — | |
| Large-to-very large | 5 (4) | 4 (1) | 2.7 (1.1–7.1) | 0.043 | |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
