Screening for significant atherosclerotic renal artery stenosis with a regression model in patients undergoing transradial coronary angiography/intervention

Clinical and angiographic features associated with coronary collateralization in stable angina patients with chronic total occlusion

OBJECTIVE

Coronary collateral circulation is an alternative source of blood supply to myocardium in the presence of advanced coronary artery disease. We sought to determine which clinical and angiographic variables are associated with collateral development in patients with stable angina and chronic total coronary occlusion.

METHODS

Demographic variables, biochemical measurements, and angiographic findings were collected from 478 patients with stable angina and chronic total coronary occlusion. The presence and extent of collaterals supplying the distal aspect of a total coronary occlusion from the contra-lateral vessel were graded from 0 to 3 according to the Rentrop scoring system.

RESULTS

Low (Rentrop score of 0 or 1) and high (Rentrop score of 2 or 3) coronary collateralizations were detected in 186 and 292 patients, respectively. Despite similar age, cigarette smoking, and medical treatment, patients with low collateralization were female in a higher proportion and less hypertensive, and had higher rates of type 2 diabetes and dyslipidemia than those with high collateralization (for all comparisons, P<0.05). In addition, patients with low collateralization exhibited more single-vessel disease, less right coronary artery occlusion, more impaired renal function, and higher serum levels of high-sensitivity C-reactive protein (hsCRP) compared with those with high collateralization. Multivariate analysis revealed that age of ≥65 years, female gender, diabetes, no history of hypertension, dyslipidemia, moderate to severe renal dysfunction, single-vessel disease, and elevated hsCRP levels were independently associated with low coronary collateralization.

CONCLUSIONS

Coronary collateralization was reduced in almost 40% of stable angina patients with chronic total occlusion, which was related to clinical and angiographic factors. The impact of coronary collateralization on outcomes after revascularization needs further investigation.

Prevalence of and risk factors of renal artery stenosis in patients with resistant hypertension

Renal artery stenosis (RAS) is a common cause of secondary hypertension. Renal artery angiography is the gold standard for diagnosing RAS. The aim of this study is to report (1) the prevalence of RAS in patients with resistant hypertension and (2) the association of RAS with peripheral vascular disease (PVD) and diabetes mellitus (DM). We studied 285 consecutive patients (mean age: 72.5 years) with resistant hypertension (systolic blood pressure >140 mm Hg despite administration of at least 3 antihypertensive drugs) who underwent renal artery angiography at Baylor Heart and Vascular Hospital from January 2006 to December 2010. Sixty-nine cases of RAS were identified (incidence: 24.2%). The propensity-adjusted analysis (controlling for clinical and nonclinical risk factors) showed a strong and significant association between RAS and PVD (odds ratio 5.15, 95% confidence interval 2.68 to 9.89, p <0.0001). However, the association between RAS and DM, a previously defined risk factor for RAS, was not significant in this cohort (odds ratio 0.63, 95% confidence interval 0.34 to 1.19, p = 0.16). In conclusion, results from this study define the prevalence of RAS in patients with resistant hypertension. Patients with PVD were found to be 5 times more likely to experience RAS than patients without PVD, whereas DM did not confer any increased risk.