Plasma lipoproteins are not related to restenosis after successful coronary angioplasty

A comparative study of restenosis rates in bare metal and drug-eluting stents

BACKGROUND

Various studies have been performed throughout the world on the rate of restenosis using bare metal stents (BMS) and drug-eluting stents (DES). The prohibitive costs associated with DES generally dictate the type of stent used, especially in developing countries. Therefore, there was a need for a study to assess the effect of various risk factors on restenosis in BMS and DES in the Indian context. A study was performed in the premier institution of the Indian Armed Forces, the Army Hospital (Research and Referral), New Delhi, India, under the aegis of the Indian Council of Medical Research (New Delhi). The profile of patients in the armed forces is inherently diverse in terms of demography, ethnicity, genetics, etc, which reflects the diverse and varied nature of the population in India.

METHODS AND RESULTS

A total of 130 patients were included in the present study. Follow-up after stent implantation was scheduled for six to nine months following the procedure to assess symptoms, drug compliance, and treadmill test and coronary angiography results, and to ascertain the incidence of restenosis. However, only 80 patients returned for follow-up and, therefore, the final analysis was based on these patients. They were segregated into BMS (n=41) and DES (n=39) groups. Restenosis occurred in 29 patients (36.3%). Nine of 39 patients with DES (23.1%) and 20 of 41 patients with BMS (48.8%) developed restenosis. There was a statistically significant relationship between restenosis and female sex, clinical presentation before intervention and at the time of follow-up evaluation (unstable angina), hypertension, positive stress test and compliance with medical therapy (P<0.05). No statistically significant relationship was observed between restenosis and age, diabetes, smoking, obesity and diet (P>0.05).

CONCLUSIONS

DES appear to reduce the restenosis rate and clinical end points, and appear to be more cost effective than BMS. Patient-related factors (eg, sex, hypertension and unstable angina) are important variables that affect the restenosis rate. Noninvasive stress testing had high positive and negative predictive values. Therefore, based on the present study, noninvasive stress testing is suggested before routine angiography at follow-up, which will reduce the need for repeat coronary angiography.

Lack of association between circulating levels of plasma oxidized low-density lipoproteins and clinical outcome after coronary stenting

BACKGROUND

We undertook this study to investigate whether there is an association between circulating oxidized low-density lipoproteins (OxLDLs) and outcome after coronary stenting.

METHODS

The study included 687 patients with coronary artery disease who underwent coronary stenting. Oxidized low-density lipoproteins were measured before coronary angiography. The median of OxLDL concentrations was 67.7 U/L. Patients were divided into 2 groups: the group with OxLDL levels < median (low OxLDL group, n = 345) and the group with OxLDL levels > or = median (high OxLDL group, n = 342). The combined incidence of major adverse cardiac events (death, myocardial infarction, and target vessel revascularization) was the primary end point. Angiographic restenosis was also evaluated.

RESULTS

The combined incidence of death, myocardial infarction, and target vessel revascularization was 27.2% (n = 94) in the low OxLDL group and 25.4% (n = 87) in the high OxLDL group (OR .92, 95% CI 0.68-1.23, P = .59). At 6-month angiography, restenosis was found in 28.1% of the patients (n = 74) in the low OxLDL group and in 24.2% of the patients (n = 61) in the high OxLDL group. (P = .31).

CONCLUSION

Our study shows no association between circulating levels of OxLDL and restenosis or other adverse events in patients with coronary artery disease after coronary stenting.

Absence of relationship between plasma Lp(a), Lp-AI, anti-oxidized LDL autoantibodies, LDL immune complexes concentrations and restenosis after percutaneous transluminal coronary angioplasty

To determine the relation between the concentration of Lp(a), LpAI, immunological markers of LDL oxidation (antioxidized-LDL autoantibodies (LDL-AB), LDL immune complexes (LDL-IC)) and restenosis after percutaneous transluminal coronary angioplasty (PTCA) in a Caucasian population (France), we studied 77 consecutive patients who successfully underwent PTCA. All were evaluated by follow-up angiography at an average of 6 months after PTCA and were divided into two groups: existence of restenosis (32 patients, group (G+)) and absence of restenosis (45 patients, negative group (G-)). The prevalence of diabetes mellitus was higher in the restenosis positive group than in the negative group (28% versus 2% respectively, P=0.001). Before and after adjustment in diabetes mellitus frequency there was no difference in the usual lipid parameters (total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, phospholipids, apolipoprotein AI, apolipoprotein B) between the two groups of patients nor in the other parameters (Before adjustment: Lp(a): 0.306+/-0.352 g/l (G+) vs. 0.263+/-0.270 g/l (G-); LpAI: 0.414+/-0.126 g/l (G+) vs. 0.390+/-0.092 g/l (G-); LDL-AB: arbitrary unit (AU) 3.75+/-1.91 (G+) vs. 3.67+/-1.24 (G-); LDL-IC: (AU) 0.93+/-0.82 (G+) vs. 0.86+/-0.44 (G-)). Spearman correlation coefficients did not report any correlation between late loss, loss index, gain and the above mentioned plasma parameters. In conclusion, usual tested plasma lipids, Lp(a), LpAI and in vivo markers of LDL oxidation (LDL-AB and LDL-IC) are not risk factors for restenosis after PTCA in this French population.