Incidence of stent thrombosis in DES

Overall incidence from multiple trials is in the range of 0.5-2%. How ever there is wide variation of the incidence depending on the multiple variables which influence its occurrence.

In a study of 3548 registry patients who received a DES, the cumulative incidence of definite, probable or possible ST was 1.8 %. The incidence for definite ST was 0.65% over a 15 month period ref1.

In a study of 1911 patients with DES and a follow up to a median 19.4 months, the overall incidence of ST was 0.8 % ref2.

In a study of 1731 patients undergoing SES implantation the cumulative one year ST rate was 1.7%. This number was 3.2% for diabetics ref3.

In a “real world” observational study involving 15157 patients with SES acturial incidence of ST at 12 months was 0.87% ref4.

Incidence of early stent thrombosis (ST) with drug eluting stents (DES)

 * This group would include
 * Incidence of intra-procedural ST with DES
 * Incidence of acute ST with DES
 * Incidence of subacute ST in DES

The rate for this group has been in the range of 0.05 – 1.1%

Intra-procedural ST occurred in 0.7% of patients in a study of 1362 partients who received a SES. The average stent legth was 42.9±28.3 mm ref5.

A rate of 0.05 % of acute ST was observed in a study of 1911 patients who were treated with aspirin, clopidogrel and on the discretion of the treating physician, GP2b3a inhibitors ref2.

In a study of 1911 patients with DES, a subacute ST of 0.05% was observed. (2) A meta-analysis of 10 RCT involving 2602 patientes who received a DES, showed a ST rate of 0.34% by 30th day. ref7.

In the real world setting a review of the e-cypher registry involving 15157 patients with SES, rate of sub-acute ST was 0.56 % ref8.

An incidence subacute ST of 0.83 % was reported in a meta-analysis of 19 RCT ref9.

In a large observational study of more than 8000 patients with DES, the cumulative incidence of subacute stent thrombosis was 1•1% at 30 days. This accounted for 60% of total ST ref10.

Incidence of late ST in DES

 * This would include
 * late ST
 * ST from 30 days to 365 days
 * Very late ST
 * ST from one year onwards
 * ST beyond 3 years

The annual incidence has been reported in the range of  0.6% to %. The reported cumulative incidence has been from %  to   %.

In a study of more than 8000 patients in two academic centers, the cumulative incidence of late stent thrombosis was 1•7% at 1 year, The slope of the linear portion of the cumulative incidence curve between 30 days and 3 years indicated a steady rate of 0•6% per year. (figure ) ref10.

In 1911 patients with DES, late ST rate was 0.6% with 100% follow up rate ref2.

A late angiographic ST rate of 0.35% (95% confidence limits 0.17% to 0.72%).was reported in a cohort of 2006 patients with 98% of the patients being followed up. The rate from 1 month to 12 months was 0.25%. If the patients who had premature cessation of antiplatelet therapy, then the incidence of late ST was 0.2% ref11.

An incidence late ST of 0.7 % was reported in a meta-analysis of 19 RCT ref9.

In a real world setting in a study involving 15157 patients with SES rate of late ST was 0.19 with an acuturial 12 month rare of 0.87% ref8.

The incidence for late ST in DES was 0.5% in a meta-analysis of 14 trials looking at 6675 patients ref12.

A meta-analysis of 10 RCT involving 2602 patients with DES revealed a late ST rate of 0.23% ref13.

In the real world setting a review of the e-cypher registry involving 15157 patients with SES, rate of late ST was 0.19 % ref8.

In a large observational study of more than 8000 patients with DES, the incidence of late stent thrombosis was 0.6%. This accounted for 40% of total number of ST ref10.

In an observational study involving 4666 patients, the outcomes were assessed on the basis of antiplatelet use as reported by the patients. The landmark analysis at 12 months suggested the lowest mortality with those who had a DES and who were on dual antiplatelet therapy. How ever only 35% of the original cohort was analyzed at 12 months. (see figure below)

Figure ref14.

The real incidence of thrombus formation inside a SES was shown in an elegent angioscopy study where 3 out of 17 stents showed very late thrombus formation at 21.2±2.2 months ref6.

In the real world setting and with SES an annual rate of 0.87 % was reported up to 3 yrs of follow up ref8.

In a large observational study of more than 8000 patients the cumulative incidence of very late stent thrombosis was 2•3% at 2 years, and 2•9% at 3 years. Late stent thrombosis occurred steadily at a constant rate of 0•6% per year up to 3 years after stent implantation with no evidence of diminution. 75% of patients were not followed up at three years and mortality data were taken from municipal registries. This process may have excluded some of the events. Therefore the number of events would have been higher than reported. (figure) ref10.

The incidence for very late ST for DES was 0.5% and that for SES was 0.36% in a meta-analysis of 14 trials looking at 6675 patients. The risk of ST with DES remained constant up to the end of follow up period of 4 yrs. ref12.

In a cohort of 2006 patients with DES and with a 98% follow up rate, a very late ST rate was 0.15% ref11.

In a study of serial angioscopy study of 17 patients with SES, 3 patients had visible thrombus at 21 months followup ref15.