A non-interventional study of microcirculation dynamics in allogeneic hematopoietic cell transplantation survivors compared to controls: evidence of impaired microvascular response regardless of conventional cardiovascular risk factors.

Allogeneic hematopoietic cell transplantation (alloHCT) survivors have been recently recognized as patients at increased cardiovascular risk. We hypothesized that vascular function remains impaired in alloHCT survivors free of graft-versus-host-disease or relapse. We enrolled consecutive adult alloHCT survivors and non-HCT control individuals (January 2019-March 2020), matched for traditional cardiovascular risk factors. Microvascular dysfunction was dynamically assessed in real time by Laser Speckle Contrast Analysis (LASCA). Carotid-femoral pulse-wave velocity (PWV) and carotid intima media thickness (IMT) were assessed as surrogate markers of cardiovascular disease. We studied 75 patients after a median of 3.2 (range 2.1-4.9) years from alloHCT, who had suffered from grade 2 to 3 acute (20%) and/or moderate/severe chronic GVHD (42%), and 75 controls. Although traditional cardiovascular risk factors and surrogate markers of cardiovascular disease did not differ between groups, alloHCT survivors showed significantly impaired microvascular function (baseline and peak flux, time to peak, base to peak and base to occlusion change). LASCA indices were also independently associated with alloHCT. Our study shows for the first-time impaired microcirculation dynamics in alloHCT survivors, independently of cardiovascular risk factors. Additional studies are needed to address the role of novel markers in cardiovascular risk prediction, along with effects of disease type, phase, and pre-transplant treatments.