Contributor: Mat Bull
Do progenitor cells matter for patients with HF? First, what is a progenitor cell? A progenitor cell is a stem cell that has potential to differentiate into multiple different cell types. Progenitor cells are classified by cluster of differentiation surface markers, which act as receptors and ligands to their target tissue. CD34+ progenitor cells have been shown to play a role in vascular and myocardial regeneration and in this article are shown to be an important biomarker in heart failure.
Progenitor cells seem to do lots of good things. Decreased circulating progenitor cells are associated with vascular disease such as atherosclerosis and endothelial dysfunction. Low levels of progenitor cells are also associated with dysfunctional cellular regeneration and repair. Progenitor cells appear to mitigate adverse left ventricular remodeling, prevent cardiomyocyte apoptosis, and stimulate angiogenesis.
514 HF patients were analyzed (330 HFrEF and 184 HFpEF). The HFrEF cohort was further divided into ICM (286) and NICM (44). These patients were then compared to over 1400 non-HF controls. This represents the largest and most powerful study to date looking at levels of circulating progenitor cells in HF patients. A separate cohort of 582 patients (137 with HF) served as a validation cohort.
So what did they find? Patients with both HFpEF and HFrEF had decreased levels of circulating progenitor cells compared to controls without HF, and this directly correlated with NYHA symptoms. Individuals with NICM had the most depressed CD34+ counts. Interestingly, low endothelial-enriched progenitor cell counts correlated with poor outcomes in HFpEF but not in HFrEF.
In a heartbeat… HF patients have lower circulating levels of progenitor cells compared to non-HF patients. Levels are predictive of HF outcomes and have distinct cellular patterns between HFpEF and HFrEF. Unlocking stem cells continues to be a promising, but unrealized, therapeutic strategy.