Patients with CKD added to list of those at risk for coronary events

Risk for coronary heart disease in patients with chronic kidney disease may be similar to that of patients with previous myocardial infarction, data published in The Lancet suggest.

Researchers used data from a large population-based cohort of nearly 1.3 million patients from Canada to analyze the risk for hospital admission for MI in those with a history of MI, diabetes, CKD or any combination of the three vs. those without disorders.

Marcello Tonelli, MD, of the department of medicine and department of public health sciences at the University of Alberta in Edmonton, Canada, and colleagues conducted the study using two datasets.

The Alberta Kidney Disease Network (AKDN) database (2002-2009) was used to evaluate risk for hospital admission for MI and all-cause death in patients aged at least 18 years with previous MIs. The second dataset, the 2003-2006 National Health and Nutrition Examination Survey, was used to estimate the number of US residents who would meet criteria for the risk groups studied.

The second dataset came from the 2002 to 2009 National Health and Nutrition Examination Survey to estimate the number of US residents who would meet the criteria for the risk groups studied. All NHANES participants were aged 20 years or older.

The five risk groups were categorized as:

Patients with previous MI (with or without diabetes and CKD).
Four mutually exclusive groups of patients without previous MI who had:
- No diabetes and no CKD.
- CKD alone.
- Diabetes alone.
- CKD and diabetes.

CKD as a risk factor

During a median follow-up of 48 months, 11,340 of 1,268,029 patients (1%) were admitted to the hospital for MI. According to data, the unadjusted rate of MI was highest in patients with a prior MI (18.5 per 1,000 person-years; 95% CI, 17.4-19.8).

Results also revealed a lower rate of MI in patients with diabetes only vs. patients with CKD only (5.4 per 1,000 person-years; 95% CI, 5.2-5.7 vs. 6.9 per 1,000 person-years; 95% CI, 6.6-7.2) among those without a prior MI.

Moreover, data show that the rate of incident MI was lower in patients with diabetes compared with patients who had CKD, defined as estimated glomerular filtration rate of less than 45 mL/min/1.73 m² and severely increased proteinuria (6.6 per 1,000 person-years; 95% CI, 6.4-6.9 vs. 12.4 per 1,000 person-years; 95% CI, 9.7-15.9), researchers wrote.

“Our research suggests that there is a strong case for considering chronic kidney disease to be a coronary heart disease risk equivalent, meaning that people with chronic kidney disease are at a comparable risk of coronary events to those who have previously had a heart attack. Chronic kidney disease patients have substantially higher rates of death from heart disease after a heart attack than the general population, which emphasizes the value of preventing coronary events through drug treatment and lifestyle interventions,” Tonelli said in a press release.

Ramifications

In an accompanying editorial, George L. Bakris, MD, member of the Endocrine Today and Cardiology Today Editorial Boards, and Tamar S. Polonsky, MD, of the Northwestern University Feinberg School of Medicine in Chicago, challenged the classification of CKD as a CHD risk equivalent.

George L. Bakris

Bakris and Polonsky wrote that some information was lacking from the study, including factors such as blood pressure and patients’ medication, which could alter the cardiovascular risk.

Despite the absence of this information, Bakris and Polonksy wrote that the large-scale study may significantly impact clinical practice.

“Their findings emphasize the importance of primary prevention, particularly because patients with chronic kidney disease comprise a large proportion of patients who have a heart attack,” they said.

Tonelli and colleagues said further studies to assess whether the findings apply throughout a long-term follow-up are needed.

For more information:

Polonsky TS. Lancet. 2012;doi:10.1016S0140-6736(12)60772-7.

Tonelli M. Lancet. 2012;doi:10.1016/S0140-6736(12)60572-8.

Disclosure: Dr. Tonelli received a research grant from Pfizer in 2006 and served on the Merck advisory boards from 2010-2011, with honoraria donated to charity. Dr. Bakris consults for Abbott, Lilly, Novartis, Roche and Takeda; and has received grants from Forest Laboratories and Takeda for investigator-initiated projects.