Multifactorial Intervention with Nurse Practitioners May Control Cardiac Risk Factors in CKD

Nurse practitioners did as well as physicians when they were part of a multifactorial program to improve management of some cardiovascular (CV) risk factors. They lessened the need for physician visits for patients with chronic kidney disease (CKD) but were unable to modify lifestyle risk factors such as smoking, body weight, physical activity, or sodium intake.

Researchers performed the Multifactorial Approach and Superior Treatment Efficacy in Renal Patients with the Aid of Nurse Practitioners (MASTERPLAN) study to investigate whether a multifactorial intervention based on guidelines with the added support of specialized nurse practitioners to augment physician visits could reduce CV risk, slow the loss of renal function, and improve the quality of care. Studies of single interventions achieved at best only moderate success in reducing the high CV morbidity and mortality accompanying CKD.

Arjan van Zuilen, MD, head of the kidney transplant unit at University Medical Center Utrecht in Utrech, Netherlands, presented the findings of the MASTERPLAN study in a late-breaking trial recently.

MASTERPLAN was a randomized controlled clinical trial that recruited patients with CKD from nine Dutch hospitals between 2004 and 2005 and followed them up through 2010. The participants’ estimated GFR had to be between 20 and 70 mL/min per 1.73 m2. They were randomly assigned to a traditional care control group (n = 393) or to an interventional group (n = 395). The primary outcome was a composite of CV death, myocardial infarction, and stroke.

At baseline, participants in the two groups were well matched for age (59 years), gender (about 68 percent men), kidney transplants (14 percent), blood pressure, estimated GFR, and laboratory parameters. However, there was more history of CV disease in the intervention group (34 percent) than in the control group (25 percent).

CV risk factors other than lifestyle improved in intervention group

At 5 years, most laboratory parameters had improved and the use of risk-reducing drugs rose in both groups, but the intervention group showed greater improvement than did the control group. It had greater decreases in systolic and diastolic blood pressure, LDL cholesterol, proteinuria, and prevalence of anemia. It also made more use of statin drugs, aspirin, and active vitamin D.

The use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers increased in both arms, with more than 80 percent of participants in each arm using them, so there was no significant difference between the groups. They also did not differ in their hemoglobin A1c levels, which were already below the treatment goal of 7.0 percent at baseline.

Although the CV risk factors improved in the intervention group compared with the control group, the intervention group had no lower incidence of the primary composite endpoint of CV death, myocardial infarction, and stroke or of any of the secondary endpoints of the risk of each individual component of the composite endpoint, or in the risk of reaching ESRD.

The intervention did not help to modify any lifestyle risk factors, such as physical activity, body mass index, or sodium intake. Both the intervention and control groups had a decrease in the proportion of smokers—the difference between groups was not significant.

Patients in the intervention group made more visits to health care providers each year (7.2 versus 4.7 visits, respectively, but they visited the physician less often than did those in the control group (2.8 versus 3.7, respectively).

Study was underpowered for primary outcome

Dr. van Zuilen explained the lack of a significant difference in the primary outcome as a result of too few CV events occurring, with a 5-year event incidence rate of 8.9 percent in both arms. When the study was planned, the estimated event rate in the control arm was 13.5 percent, based on the results of previous studies.

Johannes Mann, MD, of the department of nephrology at Munich General Hospital in Munich, Germany, said he calculated that to be sufficiently powered to show a difference in the primary endpoint, the study would have required 10 times the number of individuals involved in the MASTERPLAN trial.

In explaining the results, Dr. van Zuilen further noted that perhaps not all the treatment goals were beneficial, and that possibly, because some of the risk factors were well controlled in both groups, the differences between groups were small.

He concluded that nurse practitioners can perform as well as physicians to improve CV risk factors if they follow established guidelines and that they “can then take away some of the burden of the very big patient loads we have in our outpatient departments.”

Despite MASTERPLAN being underpowered to show an effect between groups in the primary outcome of CV death, myocardial infarction, and stroke, Dr. Mann commented to ASN Kidney News that it was “a very important study because… the nurse practitioner intervention was, in absolute terms, effective in reducing the primary outcome, which was a hard outcome.”

October-November 2011 (Vol. 3, Number 10 & 11)