Long-Term Outcomes of Percutaneous Coronary Intervention (PCI) in Octogenarians with Chronic Kidney Disease
D Bhatt, F Saeed, M Saqlain, S Arora, V Vanar, M Gibb, J Holley, S Mehta, P Kansara
chronic kidney disease, coronary atherosclerosis, in-stent restenosis, percutaneous coronary intervention pci, target vessel revascularization
D Bhatt, F Saeed, M Saqlain, S Arora, V Vanar, M Gibb, J Holley, S Mehta, P Kansara. Long-Term Outcomes of Percutaneous Coronary Intervention (PCI) in Octogenarians with Chronic Kidney Disease. The Internet Journal of Cardiology. 2012 Volume 10 Number 2.
CKD – Chronic Kidney Disease;
PCI – Percutaneous Coronary Intervention;
CVD – Cardiovascular Diseases;
BMS – Bare Metal Stents;
DES – Drug Eluting Stents;
GFR – Glomerular Filtration Rate;
TVR – Target Vessel Revascularization;
SOB – Shortness of Breath
Octogenarians are a fast growing population in the western world 1. In the United States, growth is expected in those aged 85 years or above over the next 50 years with approximately 8.5 million Americans in this age group by 20302. This population is expected to have multiple co-morbid conditions like diabetes, previous coronary artery bypass surgery, stroke, and chronic kidney disease (CKD) 3. In CKD patients, cardiovascular diseases (CVD) are a major cause of morbidity and mortality 4, 5 and CVD is strongly associated with the occurrence and progression of CKD 6. Octogenarians are increasingly referred for percutaneous coronary interventions (PCI) using either bare metal stents (BMS) or drug eluting stents (DES). Currently, limited data are available on the outcomes of PCI in octogenarian CKD patients. We reviewed our experience with PCI in octogenarians with and without CKD and compared overall mortality, in-stent re-stenosis, and bleeding complications in those treated with BMS and DES.
A total of 3,116 patients underwent coronary intervention between January 2003 and December 2009. A retrospective analysis of the 450 octogenarian patients from the 3,116 patients undergoing coronary intervention during the study period was performed. Inclusion criteria were: a) patients ≥ 80 years of age b) PCI was performed on a de-novo coronary artery or coronary artery bypass graft lesion and c) availability of serum creatinine within 30 days of PCI. Three hundred nineteen fulfilled the inclusion criteria and form the study group. The remaining patients were excluded for the following reasons: 110 patients had PCI with stent placement under the age of 80 and PCI was repeated for in-stent restenosis after they were 80 years of age, 2 patients had stent placement for coronary artery dissection, and 19 did not have serum creatinine levels drawn within 30 days of the procedure.
Chronic kidney disease was defined as an estimated glomerular filtration rate (eGFR) below 60ml/min/1.73m2 for at least a period of three months. eGFR was estimated by the MDRD 7 formula using patient’s age, serum creatinine (in mg/dl), race and gender. Patients were divided into two groups based on GFR: those with and without CKD.
Data was collected retrospectively by reviewing electronic medical records for demographic variables and other co-morbidities including hypertension, diabetes, hyperlipidemia, previous bypass surgeries, presence of peripheral vascular disease, the date of stent placement, and the date of in-stent restenosis. The primary end-point of the study was development of in-stent restenosis in each group. Secondary
The patients were stratified into two groups: CKD and non CKD. The data are presented as mean ±SD for continuous variables or as a count (%) for non-continuous variables. Statistical analysis was performed using Chi-square test and independent
Baseline clinical characteristics of the groups are shown in Table 1. One hundred forty-three (42.8%) octogenarians had CKD. CKD patients were older and more likely to have diabetes, cancer, and peripheral vascular disease. There was no significant difference between the two groups in site of stent placement, stent size and diameter, and the number of vessels stented. More CKD patients presented with either unstable angina/Non-STEMI or STEMI compared to non-CKD patients. There was no significant difference in the development of in-stent restenosis in CKD and non-CKD octogenarians. The secondary outcomes of PCI between the two groups were also not significant (Table 2). Subgroup analysis based on the type of stent in each group revealed no difference in the development of in-stent restenosis (Table 3). Cox proportionate hazards model showed that CKD patients had a shorter mean time to the development of in-stent restenosis compared to patients without CKD which was not statistically significant (14.56 ±12.8 months versus 16.72 ±12.9 months, respectively, p = <0.76). There was no significant difference in overall bleeding complications among all patients (
There are limited studies assessing outcomes of PCI in octogenarians with CKD. We show there is no significant difference in: 1) in-stent restenosis between CKD and non CKD octogenarians 2) non-fatal MI and TVR after PCI between these two groups, 3) no relationship between the type of stent placed and in-stent restenosis in either the CKD or non-CKD octogenarians, and 4) CKD patients had overall higher mortality. There was no significant difference in bleeding complications between two groups. However, CKD patients who were taking long-term aspirin and clopidogrel were more likely to suffer a bleeding complication.
Chronic kidney disease (CKD) affects a significant percentage of elderly who are the fastest growing segment of the CKD population 9. CKD is an independent predictor of myocardial infarction (MI), stroke, and all-cause mortality 5. Practice guidelines from the National Kidney Foundation in 2002 and the American College of Cardiology/American Heart Association Task Force in 2004 recommended that chronic kidney disease be considered a CHD risk equivalent 10. Moreover, CKD patients also have increased short and long term mortality after an acute coronary syndrome, irrespective of treatment 9. Thus, increasing attention is and will be devoted to cardiovascular diseases, its diagnosis, treatment, and outcomes among elderly with CKD. The relatively large number of octogenarian patients in our study confirms the frequency of invasive cardiovascular procedures performed in these patients 11 .
Multiple studies have assessed the outcomes of PCI in CKD and non-CKD patients but octogenarians were excluded from most of these studies. In moderate CKD and dialysis patients, a frequent pathological change in blood vessels is plaque calcification along with increased intimal and medial thickness 12.
Previous studies have shown that DES may reduce repeat interventions in octogenarians, but kidney function was not addressed as a distinct variable 16.
Our study shows that outcomes of BMS are comparable to DES in octogenarians with CKD. This may be clinically relevant as polypharmacy and medication costs could be reduced by avoiding long term dual anti-platelet therapy in this group of patients by avoiding DES placement. In addition, by avoiding long-term dual anti-platelet therapy we may reduce the risk of bleeding in this subset of patients. Our findings suggest that BMS implantation is an acceptable option in octogenarians, especially octogenarians with CKD.
The major limitation is the retrospective nonrandomized nature of the study .Our study was mainly restricted to CKD stage 3 and 4 and included only 4 patients with end stage renal disease. CKD was defined by the MDRD formula which may not accurately reflect kidney function in the extremes of GFR or in the elderly 26. The study population was small and mainly consisted of Caucasians due to geographic variation.
Our study shows that outcomes of BMS are comparable to DES in octogenarians with CKD. This may be clinically relevant as polypharmacy and medication costs could be reduced by avoiding long term dual anti-platelet therapy in this group of patients by avoiding DES placement. In addition, by avoiding long-term dual anti-platelet therapy we may reduce the risk of bleeding in this subset of patients. Our findings suggest that BMS implantation is an acceptable option in octogenarians, especially octogenarians with CKD. Larger studies are required to determine the best treatment options for this patient population.