Background: Microvascular blood flow alterations may impair tissue oxygenation and may participate in the development of multiple organ failure in patients with severe heart failure. We hypothesized that microvascular blood flow alterations are present in patients with severe heart failure and cardiogenic shock.
Methods: We used an orthogonal polarization spectral imaging technique to investigate the sublingual microcirculation in 40 patients with acute severe heart failure, including 31 patients with cardiogenic shock, and in a control group of 15 patients who were examined the day before cardiac surgery. The effects of topical application of acetylcholine (10-2M) were also tested in 5 patients with cardiogenic shock. Five sublingual areas were recorded, allocated a random number, and later analyzed semiquantitatively. Data were analyzed with non-parametric tests and presented as medians (percentiles 25-75).
Results: The density of all the vessels was similar in the 3 groups. The proportion of perfused small (<20 microm) vessels was lower in patients with cardiac failure and cardiogenic shock than in control patients (63% [46%-65%] and 49% [38%-64%] vs 92% [90%-93%], P <.001). The perfusion of large vessels was preserved in all groups. The proportion of perfused vessels was higher in patients who survived than in patients who did not survive in all vessels (90% [84%-93%] vs 81% [74%-87%], P <.05) and in small vessels (64% [49%-68%] vs 43% [37%-62%], P <.05). The topical application of acetylcholine totally reversed these alterations
Conclusions: Microvascular blood flow alterations are frequently observed in patients with severe heart failure and are more severe in patients who do not survive.