Decreased Kidney Function May be Associated with Coronary Spastic Angina

The results of a study titled "Influence of Early Stage Chronic Kidney Disease on Coronary Spastic Angina" were presented Monday, November 15 at the American Heart Association Scientific Sessions 2009. Because chronic kidney disease (CKD) is associated with the morbidity and mortality of cardiovascular disease "through atherosclerotic processes," researchers undertook this study to evaluate the relationship between CKD and coronary spastic angina (CSA).

Researchers identified 127 patients who underwent coronary angiography with intracoronary acetylcholine or ergonovine provocation test and evaluated them for CSA (defined as "total or subtotal coronary vasoconstriction with chest pain and ischemic ST segment changes on electrocardiography after provocation that were resolved by an intracoronary injection of isosorbide dinitrate, and the absence of organic coronary stenosis) and kidney function (determined by the estimated glomerular filtration rate, or eGFR). Patients with eGFR 29 mL/min/1.73 m² were excluded.

Fifty-three patients in the cohort had CSA; 74 did not. The researchers reported that "age and proportion of smokers, hypertension, diabetes mellitus, and obesity were similar between the two groups. Seventy-two percent of the patients with CSA were male (compared with 46% of non-CSA patients), and 49% of CSA patients also had dyslipidemia (compared with 31% of non-CSA patients).

The researchers reported that CSA patients had "significantly lower" eGFR values than non-CSA patients (70.4 ± 14.8 vs. 79.2 ± 17.2 mL/min/1.73 m², P = 0.003), and represented a higher proportion of eGFR category 59 mL/min/1.73 m²

Fifty-six percent of patients with eGFR values of < 63.9 mL/min/1.73 m² had CSA; 55% of patients with eGFR values of 63.9 - 75.0 mL/min/1.73 m²) had CSA. Twenty-three percent of patients with eGFR values 85.3 mL/min/1.73 m²) had CSA; 23% of patients with eGFR values of 75.0 - 85.3 mL/min/1.73 m² had CSA. Male gender and eGFR were independent factors associated with CSA.

The study authors concluded that "mildly and moderately decreased eGFR is associated with a higher prevalence of CSA, suggesting that early stage CKD is related to a relatively initial stage of atherosclerosis. Management for CKD might lower the incidence of CSA."