RENAL ARTERIES
It is known that there is a correlation between heart and kidney functioning with impairment of one organ affecting the work of the other76. Condition of coronary and renal arteries is an important factor used to evaluate the risk of adverse events in the organs that receive blood from mentioned vessels. Renal artery stenosis (RAS) is often found in patients diagnosed with CAD77-80 .
Conlon et al. reported that significant RAS, defined as at least 75% narrowing of the luminal diameter, was observed in 4.8% of cases of patients undergoing CA 81. The four-year unadjusted survivals for patients with and without significant RAS were 57% and 89%, respectively (p<0.001). Another study evaluated patients, with known or suspected CAD, who underwent CA and renal arteries examination 82. The prevalence of RAS of any severity among catheterized patients was 25% and among those with CAD, this figure increased to 36%. An important finding in this study was that CAD is almost invariably present in patients with even non-significant RAS and the absence of significant CAD made the likelihood of RAS of any severity extremely remote. The incidence of renal artery stenosis is high for CABG recipients as 47% of them had concomitant RAS with higher age and hypertension classified as independent factors of its occurrence 83. Przewlocki et al. aimed to determine the prevalence of RAS in 1036 patients with suspected CAD 84. RAS prevalence in patients with CAD was 38.3% (284/741) and its frequency increased with the severity of CAD: from 25% in patients with insignificant coronary lesions up to 36.4%, 40.2%, and 48% in 1, 2, and 3-VD, respectively. Data from a 5% random sample of the United States Medicare population demonstrated that of 5875 patients with RAS, 66.8% had concomitant CAD while CAD occurrence in patients without RAS was 24.9% 85. A group of 333 consecutive patients with CAD underwent CA, followed by renal angiography 20. Authors emphasized that multivessel CAD was more frequent in patients with significant RAS than with non-significant one (72,5% vs 48,1%). Imori et al. collected data from 1,734 patients with CA and renal artery Doppler US14. Among those patients with CAD, 9% were simultaneously diagnosed with RAS. The extent of CAD was related to the prevalence of RAS, most significantly expressed with the 3-vessel disease. Not only significant stenosis (>50%) of the renal artery is correlated with CAD. The examination of 1,561 hypertensive patients showed that 71 of them had RAS and 126 - arteriosclerotic plaque (ARAP) without significant stenosis 86. The occurrence of CAD was higher in both groups (80%; 70%) compared to patients without any stenoses (56,5%). The 9-year follow-up revealed that RAS and ARAP are independent factors of CAD development and severity. Another study focused on the importance of non-hemodynamically significant RAS in patients with CAD 87. Of the 623 enrolled patients, RAS was confirmed in 181 cases. The median 4.5-year follow-up stated that the presence of RAS was associated with more CVE compared to the group without the diagnosis (35.4% vs. 24.7%). Edwards et al. observed among 870 patients after renal artery Doppler US, during a mean follow-up of 14 months, that the presence of renovascular disease demonstrated a significant relationship with adverse coronary events (HR 1.96) 88.