TCT Feature: Resolute may resolve bad outcomes for diabetics
When diabetic patients were treated with either the Resolute zotarolimus-eluting stent or Xience V everolimus-eluting stent (EES), they saw similar one-year outcomes, Sigmund Silber, MD, director of the Heart Centre at the Isar in Munich, presented Nov. 8 at the 23rd annual Transcatheter Cardiovascular Therapeutics (TCT) conference in San Francisco. Additionally, even in non-insulin dependent diabetes patients treated with the Resolute stent, clinical outcomes were similar to those outcomes seen in the non-diabetic population.

“People with diabetes and heart disease constitute about one-third of the patients that receive PCIs worldwide,” Silber explained
According to Silber, diabetic patients have higher event rates due to:
  • Endothelial dysfunction;
  • Impaired platelet function;
  • Altered coagulation/fibrinolysis; and
  • Increased smooth muscle cell proliferation.

For the current presentation, patient level data from five RESOLUTE clinical trials—RESOLUTE, RESOLUTE All Comers, RESOLUTE International, RESOLUTE US and RESOLUTE Japan—were pooled together to evaluate the outcomes of diabetic patients treated with the Resolute ZES stent compared with those treated with the Xience V EES. In the RESOLUTE All Comers trial, the Resolute ZES was found to be equivalent to the Xience V EES. The RESOLUTE clinical trial, enrolled 2,292 patients who were randomized to receive either the Resolute zotarolimus-eluting or an everolimus-eluting stent (Xience V, Abbott Vascular).

When these data were pooled together, the researchers were left with 5,130 patients treated with the Resolute ZES. Of these patients, 1,535 patients were diabetics and treated with a Resolute DES. The researchers compared the outcomes for those who received a Xience V DES and those who received the Resolute stent.

Results showed that when newer generation DES (Xience and Resolute) were compared, results were similar, Silber told Cardiovascular Business. “These two stents have a similar chemical structure and the question was: what are the differences in outcomes between these two stents?

“The All Comers trials showed that there are no differences between these two stents and that they are very much equivalent,” he noted. “The other question was about patients with type 2 diabetes.

“If you look at those patients that have diabetes and who do not have diabetes, we found that in the diabetic population there was no substantial difference between both the Resolute and Xience stents.”

The primary endpoint of target lesion failure (TLF) occurred in 9 percent of diabetic patients treated with the Xience EES stent and 7.8 percent of patients treated with the Resolute stent. In non-diabetics, TLF occurred in 6.1 percent of patients treated with the Resolute stent and 8.3 percent of patients treated with the Xience EES. Meanwhile, target lesion revascularization (TLR) occurred in 5 percent of diabetic patients treated with Xience EES and 4 percent of patients treated with Resolute.

For cardiac death and target vessel MI, diabetics treated with the Resolute stent saw an event rate that equated to 4.7 percent compared with diabetics treated with the Xience EES stent, who saw event rates equal to 4.9 percent. In comparison, non-diabetics treated with Resolute stents saw cardiac death and target vessel MI rates equal to 3.6 percent compared with non-diabetics treated with Xience EES stents who saw event rates of 5.7 percent.

“Resolute stents in patients with diabetes garnered the same results of patients who did not have diabetes,” Silber noted.  “These results are very encouraging because usually diabetic patients do worse than non-diabetic patients.

“In these circumstances the results were the same, so you could say if you used the Resolute stent, you make a diabetic patient prognosis like a non-diabetic patient; however, this is not the same for patients on insulin,” Silber said.

Diabetic patients on insulin see higher major adverse cardiac event (MACE) rates and higher rates of complication. For example, TLR occurred at a rate of 6.3 percent in insulin-dependent diabetes patients and these rates were 3.1 percent for non-insulin dependent diabetic patients.

“So, what is the difference between the insulin dependent and non-insulin dependent patients?” Silber asked.  Insulin dependent patients are sicker and see worse outcomes.

“The take home messages here is that non-insulin dependent diabetics have the same outcomes with the Resolute stent compared with non-diabetics,” Silber concluded. In the RESOLUTE pooled patient level analysis, non-diabetes patients saw cardiac death rates equal to 3.6 percent with the Resolute ZES stent compared with the 3.8 percent event rate for non-insulin dependent diabetes patients.

Additionally, Silber concluded that there was no difference in one-year outcomes in diabetic patients treated with either the Resolute ZES or Xience EES.

However, Silber said that while good results were observed for patients who were insulin-dependent diabetic patients, there is still room for improvement.