CILP1 as a biomarker for right ventricular dysfunction in patients with ischemic cardiomyopathy

CILP-1 Is a Biomarker for Backward Failure and Right Ventricular Dysfunction in HFrEF

BACKGROUND

CILP-1 regulates myocardial fibrotic response and remodeling and was reported to indicate right ventricular dysfunction (RVD) in pulmonary hypertension (PH) and heart failure (HF). This study examines CILP-1 as a potential biomarker for RVD and prognosis in heart failure with reduced ejection fraction (HFrEF) patients on guideline-directed medical therapy.

METHODS

CILP-1 levels were measured in 610 HFrEF patients from a prospective registry with biobanking (2016-2022). Correlations with echocardiographic and hemodynamic data and its association with RVD and prognosis were analyzed.

RESULTS

The median age was 62 years (Q1-Q3: 52-72), 77.7% of patients were male, and the median NT-proBNP was 1810 pg/mL (Q1-Q3: 712-3962). CILP-1 levels increased with HF severity, as indicated by NT-proBNP and NYHA class (p < 0.0001, for both). CILP-1 showed a weak-moderate direct association with increased left ventricular filling pressures and its sequalae, i.e., backward failure (LA diameter rs = 0.15, p = 0.001; sPAP rs = 0.28, p = 0.010; RVF rs = 0.218, p < 0.0001), but not with cardiac index (CI) and systemic vascular resistance (SVR). CILP-1 trended as a risk factor for all-cause mortality (crude HR for 500 pg/mL increase: 1.03 (95%CI: 1.00-1.06), p = 0.053) but lost significance when it was adjusted for NT-proBNP (adj. HR: 1.00 (95%CI: 1.00-1.00), p = 0.770). No association with cardiovascular hospitalization was observed.

CONCLUSIONS

CILP-1 correlates with HFrEF severity and may indicate an elevated risk for all-cause mortality, though it is not independent from NT-proBNP. Increased CILP-1 is associated with backward failure and RVD rather than forward failure. Whether CILP-1 release in this context is based on elevated pulmonary pressures or is specific to RVD needs to be further investigated.

Assessment and diagnosis of right ventricular failure-retrospection and future directions

The right ventricle (RV) has a critical role in hemodynamics and right ventricular failure (RVF) often leads to poor clinical outcome. Despite the clinical importance of RVF, its definition and recognition currently rely on patients' symptoms and signs, rather than on objective parameters from quantifying RV dimensions and function. A key challenge is the geometrical complexity of the RV, which often makes it difficult to assess RV function accurately. There are several assessment modalities currently utilized in the clinical settings. Each diagnostic investigation has both advantages and limitations according to its characteristics. The purpose of this review is to reflect on the current diagnostic tools, consider the potential technological advancements and propose how to improve the assessment of right ventricular failure. Advanced technique such as automatic evaluation with artificial intelligence and 3-dimensional assessment for the complex RV structure has a potential to improve RV assessment by increasing accuracy and reproducibility of the measurements. Further, noninvasive assessments for RV-pulmonary artery coupling and right and left ventricular interaction are also warranted to overcome the load-related limitations for the accurate evaluation of RV contractile function. Future studies to cross-validate the advanced technologies in various populations are required.