Medical Student University of Pennsylvania Philadelphia, Pennsylvania, United States
Disclosure(s):
Jacob Niculcea, BS: No financial relationships to disclose
Background: Microcirculatory blood flow is critical for tissue oxygen delivery. However, microcirculatory function is altered in acute and chronic cardiovascular diseases, and microcirculatory dysfunction is associated with worse outcomes in cardiogenic shock. Here, we compare microcirculatory hemodynamics in patients with cardiogenic shock to age-sex-comorbidity matched controls with stable, chronic cardiovascular disease.
Methods: Single-center observational study of microcirculatory hemodynamics assessed by sublingual incident dark-field videomicroscopy (CytoCam, Braedius Medical). Cardiogenic shock patients were imaged during inpatient admission. Control data was acquired from a database of sublingual microcirculation in patients with chronic cardiovascular disease assessed during outpatient clinic visits. Microvascular flow index (MFI), microvascular heterogeneity index (MHI), proportion of perfused vessels (PPV), and perfused vessel density (PVD) were measured. Patients were matched on age, sex, diabetes, chronic dialysis, and estimated glomerular filtration rate using optimal distance minimization. Covariate balance was assessed with absolute standardized mean difference. Continuous data was compared with Wilcoxon rank sum test.
Outcome: 30 cardiogenic shock patients were matched to 30 controls. Shock patients averaged 54 (45-61) years compared to 56 (51-63) in controls. 26 (87%) patients were male in both groups. Most shock patients were SCAI stages D (15, 50%) and C (12, 40%). Average MAP in shock patients was 77±10 compared to 98±15 in controls. Cardiogenic shock patients had statistically significant impairments in microcirculatory blood flow (MFI, PPV, PVD) and greater flow heterogeneity (MHI) compared with ambulatory control patients (all p < 0.05) (Figure).
Conclusion: Cardiogenic shock patients have impaired microcirculatory function compared to matched controls with chronic cardiovascular disease. Moreover, microcirculatory impairments were observed in shock patients despite adequate resuscitation of macrocirculatory hemodynamics. The decoupling of systemic hemodynamic measurements from microcirculatory perfusion is a limitation of current protocols for treating shock.
