SIMPLE II: Safety and Efficacy of the Infinnium Paclitaxel-Eluting Stent
"All we can conclude from the SIMPLE II data is that the use of this new (less expensive) drug-eluting stent appears to be safe and effective in preventing restenosis. We will need more studies in order to really appreciate the device's true potential."

Presenter: D.S. Gambhir, MD (Kailash Heart Institute, Noida, India)

Despite the clinical and marketing success of the various drug-eluting stents introduced to the market, economics still plays a decisive role in the widespread use of these stents, especially in countries outside the United States. The Safety and Efficacy of the Infinnium Paclitaxel-Eluting Stent II (SIMPLE II) study is a prospective, multicenter study that assessed the safety and efficacy of the Infinnium stent (Sahajanand Medical Technologies, Surat, India) -- a less expensive, indigenously designed, biodegradable, polymer, paclitaxel-eluting stent.

Primary Endpoints

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  Safety: incidence of major adverse cardiac events (MACE) (cardiac death, myocardial infarction, emergent cardiac surgery, and clinically justified target lesion revascularization [TLR]) at 30 days
  
  
  
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  Efficacy: angiographic binary restenosis rate at 6-month angiographic follow-up
  

Secondary Endpoints

Safety:

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  Occurrence of MACE at 9 months
  
  
  
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  Device-related serious adverse events at 9 months
  
  
  
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  Angiographic stent thrombosis (subacute and late)
  

Efficacy:

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  Acute gain, minimal lumen diameter, percent diameter stenosis, late loss
  
  
  
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  Angiographic success
  
  
  
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  Procedural success
  
  
  
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  Clinically justified TLR at 9 months
  

Results
SIMPLE II enrolled 103 patients at 3 centers (1 in Brazil, 1 in India, and 1 in The Netherlands). Clinical and angiographic follow-up is available for 101 patients (98%). Baseline clinical characteristics are shown in Table 1.
Table 1. SIMPLE II: Baseline Characteristics

	(N = 103)
Age (yrs)	59
Female (%)	29
Diabetes (%)	28
Hypertension (%)	62
Hyperlipidemia (%)	52
Smoker (%)	32
S/P MI (%)	39
S/P PCI (%)	6
S/P CABG (%)	2

CABG = coronary artery bypass graft; MI = myocardial infarction; PCI = percutaneous coronary intervention; S/P = status-post
Clinical outcomes at 30-day and 9-month follow-up were favorable. At 30 days, there were no cardiac deaths and 3 cases of non-Q-wave myocardial infarction. At 9-month follow-up, there was 1 case of late stent thrombosis with a TLR rate of 1% (Table 2).
Table 2. SIMPLE II: Clinical Events at 270 Days

Event	(N = 103)
Cardiac death (%)	1.0
MI
Q-wave (%)	1.0
Non-Q-wave (%)	2.9
TLR
CABG (%)	1.9
Re-PCI (%)	2.9
Total MACE (%)	9.7
Stent thrombosis
Subacute (%)	0.0
Late (%)	1.0

CABG = coronary artery bypass graft surgery; MACE = major adverse cardiac events; MI = myocardial infarction; TLR = target lesion revascularization
Angiographic follow-up at 6 months was available in 96 patients and showed a late loss of 0.38 ± 0.49 mm (Table 3). The binary in-stent restenosis rate was 7.3% and the rate of in-segment restenosis was 8.3%.
Table 3. SIMPLE II: Angiographic Characteristics at 6-Month Follow-up

Parameter	(N = 96)
Stent length (mm)	17.5 ± 4.1
Reference vessel diameter (mm)	2.68 ± 0.43
Minimal lumen diameter (mm)	2.02 ± 0.59
In-stent late loss (mm)	0.38 ± 0.49
In-segment late loss (mm)	0.18 ± 0.46

Conclusions

1. 
   The biodegradable polymer-based paclitaxel-eluting Infinnium stent appears to be safe and effective in reducing restenosis at 6 months and is associated with an acceptable rate of cardiac events.
   
   
   
2. 
   Infinnium is the first indigenously designed and evaluated, low-cost, drug-eluting stent from Asia to have obtained a CE Quality Certificate for commercialization in Europe.
   

Viewpoint
The idea of a less expensive drug-eluting stent has been around for some time now. India accepted the challenge and appears to have succeeded in creating such a stent.

Due to time restraints imposed on the lecturers, very few data were presented regarding some basic aspects of the stent, as well as the polymer and the drug.

All we can conclude from the SIMPLE II data is that the use of this new (less expensive) drug-eluting stent appears to be safe and effective in preventing restenosis. These preliminary results suggests that the Infinnium stent may provide comparable results to those seen with currently available paclitaxel-eluting stents. We will need more studies in order to really appreciate the device's true potential.