Right atrial volume index to left atrial volume index ratio is associated with adverse clinical outcomes in cardiogenic shock.

Background: Structural remodeling in chronic systolic heart failure (HF) is associated with neurohormonal and hemodynamic perturbations among HF patients presenting with cardiogenic shock (CS) and HF. Our objective was to test the hypothesis was that atrial remodeling marked by an increased right atrial volume index (RAVI) to left atrial volume index (LAVI) ratio is associated with adverse clinical outcomes in CS.

Methods: Patients in this cohort were admitted to the intensive care unit with evidence of congestion (pulmonary capillary wedge pressure > 15) and cardiogenic shock (cardiac index < 2.2, systolic blood pressure < 90 mmHg, and clinical evidence supporting CS) and had an echocardiogram at the time of admission. RAVI was measured using Simpson's method in the apical four-chamber view, while LAVI was measured using the biplane disc summation method in the four and two-chamber views by two independent observers. Cox proportional hazards regression analysis was used to assess the association of RAVI-LAVI with the combined outcome of death or left ventricular assist device (LVAD).

Results: Among 113 patients (mean age 59 ± 14.9 years, 29.2% female), median RAVI/LAVI was 0.84. During a median follow-up of 12 months, 43 patients died, and 65 patients had the combined outcomes of death or LVAD. Patients with RAVI/LAVI ratio above the median had a greater incidence of death or LVAD (Log-rank p ≤ 0.001), and increasing RAVI/LAVI was significantly associated with the outcomes of death or LVAD (HR 1.71 95% CI 1.11-2.64, chi square 5.91, p = 0.010) even after adjustment for patient characteristics, echocardiographic and hemodynamic variables.

Conclusion: RAVI/LAVI is an easily assessed novel echocardiographic parameter strongly associated with the survival and or the need for mechanical circulatory support in patients with CS.