Post-procedure comparison of cardiovascular events was performed between patients who underwent either PCI or CABG depending on the severity of renal dysfunction

Significant increase of cardiovascular events was shown from patients with moderate or more severe renal dysfunction with no difference in procedure type and operative outcomes

Professor Duk-Woo Park, “Care to prevent renal failure should be provided while undergoing coronary revascularization”

▲ (from the left) Professor Duk-Woo Park, Professor Seung-Jung Park, and Professor Tae-Oh Kim

It is commonly understood that the incidence of cardiovascular disease increases when renal failure persists over at least 3 months or when one has chronic kidney disease with renal insufficiency. However, it is still not known exactly from what stage of renal failure the incidence of cardiovascular disease is impacted.

The team led by Professor Duk-Woo Park, Professor Seung-Jung Park, and Professor Tae-Oh Kim of the Division of Cardiology classified 10,354 patients who were treated for coronary artery disease depending on the severity of renal dysfunction and compared the incidence of death, spontaneous myocardial infarction, and stroke. The team revealed that, according to the research, the incidence of cardiovascular events was similar to that of individuals with normal kidney function in the case of mild renal dysfunction whereas moderate renal dysfunction was found to have a significant influence on cardiovascular events with 8.2% difference to individuals with normal kidney function.

The heart and kidney are known as body organs like brothers and sisters. Renal failure is particularly pointed out as an important risk factor for the prognosis of percutaneous coronary intervention (PCI) (stent insertion) or coronary artery bypass grafting (CABG) in coronary diseases treatment.

The research findings were published in the recent volume of the Journal of the American College of Cardiology (JACC, IF: 24.09), one of the most prestigious journals in the world in the field of cardiology.

The research team studied 6,466 patients who underwent PCI and 3,888 patients who underwent CABG during 2003 and 2018, all due to mutivessel cardiovascular disease.

According to the estimated glomerular filtration rate (eGFR)* which is a renal function index indicating how much blood the kidney can filter, the research subjects were classified into normal renal function (eGFR 90ml/min/1.73㎡ or above), mild dysfunction (eGFR 60~89ml/min/1.73㎡) and moderate dysfunction (eGFR 30~59ml/min/1.73㎡).

* Estimated glomerular filtration rate (eGFR): Estimation of renal function calculated using serum creatinine, additionally compensated for age and gender status to reflect actual renal function

After having the estimation further compensated for age, frequency of underlying diseases such as diabetes and hypertension and the degree of risk according to the severity of coronary artery diseases, an analysis was conducted on the probability of one or more cardiovascular events (death, spontaneous myocardial infarction, or stroke) between the normal function group and the mild renal dysfunction group, and between the normal function group and the moderate renal dysfunction group.

In the comparison between the normal function group and the mild renal dysfunction group, no significant difference was observed since renal dysfunction occurred in 18.0% of the normal function group and 19.6% in the mild renal dysfunction group. On the other hand, a significant difference was observed between the normal function group and moderate renal dysfunction group as renal dysfunction occurred in 25.4% and 33.6% in the groups, respectively.

This indicates that cardiovascular events such as death, spontaneous myocardial infarction, and stroke that are possible prognostic outcomes of PCI and CABG are impacted when the severity of renal dysfunction is moderate at the least.

Furthermore, the research team compared treatment outcomes of PCI and CABG according to the severity of renal dysfunction. As a result, no significant difference was demonstrated between percutaneous coronary intervention and coronary bypass surgery in all normal, mild, and moderate renal function.

In terms of severe- and end-stage renal dysfunction, it was reported from previous research that CABG produces better long-term treatment outcomes than PCI. Outcomes for mild and moderate renal failure have been revealed through this study more in detail.

Professor Duk-Woo Park said, “While previous studies on cardiovascular diseases so far have mainly been on patients with at least severe-level renal dysfunction, this study focused on borderline patients with mild and moderate renal dysfunction who had been ruled out before.”

He added, “Given that the incidence of major cardiovascular events significantly increases in patients with moderate or more severe renal dysfunction, efforts should be made to provide constant medical care to prevent renal failure while treating cardiovascular disease so that the renal failure can be maintained at a normal or mild level of severity.”