Peripheral perfusion in CAD patients with various-stage chronic heart failure undergoing coronary artery bypass grafting

Kamenskaya O.V.1, Klinkova A.S.1, Khabarov D.V.2

1) Novosibirsk Scientific Research Institute of Circulatory Pathology named after Academician E.N. Meshalkin under the RF Ministry of Public Health,
2) Scientific Research Institute of Clinical and Experimental Lymphology under the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia

Using the orthostatic test, we examined peripheral perfusion by means of laser Doppler flowmetry (LDF) and transcutaneous oximetry in a total of 104 patients presenting with coronary artery disease and functional class II–IV chronic heart failure (CHF) prior to coronary artery bypass grafting (CABG) and in the remote terms thereafter.

Volumetric velocity of the microcirculatory blood flow (MCB) of the lower limbs was measured by means of LDF in perfusion units; partial oxygen pressure (TcPO₂, mmHg) was registered by means of transcutaneous oximetry. The patients with CAD were subdivided into two groups as follows: Group One comprised patients with FC II CHF and Group Two included those with FC III–IV CHF.

Prior to CABG according to the findings of LDF, the lowest level of MCB of the lower limbs was revealed in Group Two, being by 57.9% (42.5–61.3) less as compared with Group One (p=0.008). In Group Two patients as compared with Group One there was a larger proportion of patients with impaired reactivity of the peripheral microcirculatory bed during the orthostatic test in the form of: 1) a paradoxical reaction of the MCB both before CABG (60.6 versus 13.9%, p=0.00001) and in the remote terms after the operation (64.3 versus 16.2%, p=0.00001); 2) lack of the reaction of the MCB prior to the operation (19.7 versus 4.7%, p=0.02) and in the remote period after CABG (16.7 versus 2.7%, p=0.04). Group Two patients both before and after CABG were found to have a decrease (compared with the norm) in the TcPO₂ parameters at rest, as well as lower reactivity of tissue metabolism of peripheral tissues during the orthostatic test.

An initial decrease in the left ventricular output fraction of <42% increases the chances of preserving the post-CABG decreased values of TcPO₂ of less than 24 mm Hg (OR=3.1; 95% CI 1.1–6.8; p=0.003). Lack of the reaction of the MCB during the orthostatic test prior to CABG increases the chances for the development of surgically significant atherosclerotic lesions of lower-limb arteries after myocardial revascularization (OR=4.2; 95% CI 1.3–2.3; p=0.01).

Hence, the most pronounced impairments of the mechanisms of adaptation of the MCB in the orthostatic test prior to and in the remote terms after CABG were detected in CAD patients with FC III–IV CHF. A decrease in the microvascular tonicity during the test and, consequently, inhibition of the nutritive component in this cohort of patients were accompanied by low metabolic reactivity of peripheral tissues.

KEY WORDS: coronary artery disease, coronary artery bypass grafting, microcirculation, peripheral perfusion, chronic heart failure.

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