DISCUSSION
As the main results of our study, the history of ACKD remains independently associated with in-hospital death following PCI even after adjusting baseline parameters such as other cardiovascular risk profiles. In many studies, chronic renal failure, especially frequent dialysis, has been declared as a potential risk factor for adverse outcomes of therapeutic interventions in patients with coronary heart disease, especially following revascularization (13-17). This higher mortality can be explained by the use of contrast material, disorders related to circulating blood volume, thromboembolic disorders related to kidney disease, and significant hemodynamic disorders in the mentioned patients (18-20). However, a study that enrolled 344 patients who underwent elective PCI demonstrated that there was no connection between CKD and periprocedural myocardial injury after elective PCI (21). Therefore, it is still unclear whether patients with ACKD will benefit from such procedures or not. What we found in the present study was that, firstly, the presence of ACKD is a potential risk factor for increasing the risk of hospital mortality in patients undergoing PCI. Thus, along with other background risk factors, the role of ACKD can be considered prominent in mortality risk. Considering that this result was obtained by examining a large volume of PCI candidate patients, we can emphasize the solidity and reliability of the mentioned finding. Therefore, if the patient who is a candidate for this procedure was suffering from ACKD at the time of admission, to reduce morbidity and mortality after the procedure, potential measures such as control and monitoring of kidney function should be considered, especially in intensive care units. Various strategies have been considered to reduce the risk of mortality and complications after PCI in patients with ACKD. In this regard, volume expansion within the procedure, limiting contrast use, and the use of low- to iso-osmolar contrast agents can significantly reduce the risk for postoperative death (22-23).
Most of the previous studies also emphasize chronic renal failure as a potential risk factor for worse outcomes after PCI. As similarly shown by Yager et al in 2022 (24), advanced kidney disease was linked with noticeably increased post-nonemergent PCI mortality. Narcisse et al in 2020 (25) also showed that patients with chronic kidney disease remain at greater risk for major adverse vascular events and all-cause mortality after vascular interventions.
Additionally, it should be kept in mind that due to the extent of coronary artery involvement in many patients with ACKD, invasive procedures such as coronary artery bypass surgery or PCI are absolutely unavoidable in many of these patients. Choosing the most proper and safest approach for these patients is complex. Although, several studies have demonstrated that the PCI procedure is safer compared to medical treatments and PCI has not been reported to be associated with an increased risk of death. As indicated by Yong et al in 2021 (26), in patients with advanced kidney disease and coronary artery disease, PCI reduced the risk of short-, medium- and long-term all-cause death in contrast to medical treatment. However, in their study, coronary artery bypass grafting was associated with a higher risk of short-term death and a lower risk of long-term death and adverse events compared to PCI.
In our study, the increasing trend of performing PCI procedures in patients with ACKD was demonstrated. Patel et al in 2017 (27) have shown that increasing utilization of PCI among ACS patients with ACKD has led to a lower in-patient mortality in this population. The reason for this increase can be due to the advanced techniques of performing PCI, the use of safer contracting materials as well as ultra-low contrast angiography and zero-contrast PCI, more precise control of the mentioned patients during and after the operation, as well as the general modification of the protocols and guidelines for the care of these patients and more experienced operator performing PCI which may lead to lower risk of morbidity and mortality of PCI in CKD patients (28-30).