The use of newer technologies in renal artery stenting, such as drug-eluting stents (DES), distal protection devices and intravascular ultrasound (IVUS), appear to have no advantageous effect on re-hospitalization and mortality and add more than $43,000 to the healthcare system, according to a retrospective study presented May 9 as a scientific poster at the 35th annual meeting of the Society for Cardiovascular Angiography and Interventions (SCAI). The study co-investigator told Cardiovascular Business that larger, prospective trials are needed to validate the use of these technologies.
Technical advances in renal artery stenting (RAS) may be beneficial in certain patients, however, they are coupled with increased financial costs to both patients and hospitals, wrote the study authors.
More research is needed to determine “which patients will maximally benefit from using these technologies,” said study co-investigator Mohammed Kaswara, MD, of Charleston Area Medical Center in Charleston, W.Va. “Therefore, in this study, we sought to examine if new innovations—namely, IVUS, protection devices and DES—impact the clinical outcomes and economic burden in renal artery endovascular interventions.”
The researchers retrospectively reviewed 222 renal artery angioplasty and stenting procedures performed in 189 patients at Charleston Area Medical Center from July 1, 2007 to June 30, 2010. For patient outcomes, they assessed all-cause mortality and re-hospitalization for congestive heart failure, renal failure, hypertensive crisis and target vessel revascularization (TVR).
Overall, 48 patients received IVUS during their RAS, six patients received distal protection devices and five received DES. The median follow-up period was 33 months. These patients were compared with patients with renovascular conditions at their facility who did not receive any these technologies between 1993 and 2004.
Kaswara and colleagues found that TVR was required following 18 procedures while re-hospitalization for congestive heart failure, renal failure or hypertensive crisis occurred in 17 patients. Cumulative patient survival for years one through four was 98.2 percent, 93.4 percent, 86.4 percent and 63 percent, respectively. Also, they reported that the rates of TVR, readmission and all-cause mortality were not affected by the use of IVUS, distal filter or DES.
“The lack of survival benefit for these patients who received the newer technologies is noteworthy,” Kaswara said.
The researchers also found that these three technologies contributed a substantial additional financial burden of $31,920 for IVUS (48 x $665), $7,350 for distal protection filters (6 x $1,225) and $4,000 for DES (5 x $800)—totaling $43,270.
“Because these dollar amounts are associated with a single institution, if you apply these figures across the U.S., the total is much, much higher, especially when we’re not certain of the clinical benefits of the technologies,” said Kaswara.
However, he acknowledged that the small size of the patient population did not allow for statistically significant P values; therefore, "these findings will not change practice." The researchers, as a group, also pointed to their small sample size as a limitation of their study.
“Larger, prospective studies are needed to show the clinical benefits of these devices,” Kaswara said.