C Reactive Protein, Albumin, Lymphocyte(CALLY) index predicts 12 month need for durable LVAD in patients with HFrEF
C Tunca, F Oguz, B Ozlek, V,O TanikAbstract
Background
Despite advances in guideline-directed medical therapy, timely identification of patients transitioning from chronic HFrEF to advanced heart failure remains suboptimal, often leading to delayed referral for durable LVAD support and missed "window of opportunity". An inexpensive biomarker integrating inflammation, nutritional reserve, and immune status could facilitate earlier recognition of high-risk patients before overt hemodynamic deterioration.
Purpose
To evaluate whether baseline CALLY index predicts 12-month need for durable LVAD therapy in HFrEF and to assess its value for early advanced HF referral pathways.
Methods
In a retrospective cohort of consecutive HFrEF patients (LVEF ≤35%) followed in tertiary heart failure clinics between 2019–2024, CALLY was calculated as (serum albumin × lymphocyte count) / CRP using baseline laboratory values. The primary endpoint was 12-month durable LVAD requirement, defined as LVAD implantation or formal LVAD listing/decision by an advanced HF board. Time-to-event analyses used Kaplan–Meier curves (LVAD-free survival) and log-rank testing after stratifying CALLY as low vs high (cut-off: 0.90, pre-specified for interpretability). Independent associations were assessed using Cox proportional hazards regression adjusted for age, LVEF, NYHA class, systolic BP, eGFR, and NT-proBNP. Model discrimination was summarized using Harrell’s C-statistic.
Results
Among 620 patients (mean age 60±12 years; 72% male; median LVEF 28% [IQR 22–32]), 58 (9.4%) met the primary endpoint within 12 months. Patients requiring LVAD had markedly lower baseline CALLY (median 0.62 [0.40–0.88] vs 1.58 [1.05–2.30], p<0.001) and a worse congestion/organ dysfunction profile (lower SBP and eGFR, higher NT-proBNP). Kaplan–Meier analysis showed significantly lower 12-month LVAD-free survival in the low-CALLY group (82% vs 96%, log-rank p<0.001). In multivariable Cox analysis, CALLY remained independently associated with LVAD requirement (per 1-unit increase: HR 0.55, 95% CI 0.41–0.73; p<0.001), together with NYHA III–IV, lower SBP, and higher NT-proBNP. Adding CALLY to the clinical model improved discrimination (Harrell’s C from 0.74 to 0.81).
Conclusion
Lower baseline CALLY independently predicted 12-month durable LVAD requirement and improved risk discrimination beyond conventional clinical variables. CALLY may support earlier referral to advanced HF centers and more timely LVAD evaluation by identifying high-risk patients before overt hemodynamic collapse.Figure 1For image description, please refer to the figure legend and surrounding text.