Anemia is associated with an increased central venous pressure and mortality in a broad spectrum of cardiovascular patients.

BACKGROUND: Anemia is frequently observed in patients with cardiovascular disease. Multiple factors have been associated with anemia, but the role of hemodynamics is largely unknown. Therefore, we investigated the association between hemoglobin (Hb) levels, hemodynamics and outcome in a broad spectrum of cardiovascular patients. METHODS AND
RESULTS: A total of 2,009 patients who underwent right heart catheterization at the University Medical Center Groningen, the Netherlands, between 1989 and 2006 were identified and data were extracted from electronic databases. Anemia was defined by the WHO criteria (male, hemoglobin <13.0 g/dL; female, hemoglobin <12.0 g/dL). The associations between central venous pressure (CVP), cardiac index (CI), systemic vascular resistance (SVR), hemoglobin (Hb), anemia and all-cause mortality were assessed with linear, logistic and Cox-proportional hazards analysis. The mean age was 57 ± 15 years, 57 % were male, mean Hb was 13.2 ± 0.4 g/dL, and 27.4 % of the patients were anemic. Patients with anemia had higher CVP levels (7.0 ± 5.4 mmHg) compared to non-anemic patients (5.6 ± 4.1 mmHg; p < 0.001). CI was higher in anemic patients; 3.0 ± 2.9 vs. 2.9 ± 0.8 L/min/m(2) (p < 0.001), whereas SVR was lower (1,212 ± 479 vs. 1,356 ± 555 dyn s cm(-5), p < 0.001). CVP and CI were both independent predictors of anemia (OR 1.49; CI 1.24-1.81, p < 0.001 and OR 1.93; CI 1.54-2.42, p < 0.001, respectively). Hemoglobin and CVP were both independent predictors of survival. Independent of CI and renal function, patients with anemia and an elevated CVP had the worst prognosis (HR 2.17; 95 % CI 1.62-2.90; p < 0.001).
CONCLUSION: Anemia is common in cardiovascular patients and independently related to an elevated CVP and CI. Patients with anemia and an elevated CVP have the worst prognosis.