Lessons from Studies with Drug Eluting Stents

The Big Heart Disease Lie

Reverse Heart Disease Today

Get Instant Access

Randomized Studies

As with bare metal stents, data from randomized studies comparing drug-eluting stents with CABG for unprotected left main coronary artery disease are not yet available. Several randomized studies addressing this issue are underway.

Registries

Several registries have addressed the efficacy and safety of drug-eluting stents in the treatment of left main coronary artery disease. In 2005, three key studies were published that comprised cohorts of 85 to 102 patients treated with drug-eluting stents for

Table 6-4. Mid-Term Outcome After Implantation of Drug-Eluting Stents (DES) versus Bare Metal Stents (BMS) for Unprotected Left Main Coronary Artery Disease

Parameter

Valgimigli et al79

Park et al77

Chieffo et al78

DES

BMS

DES

BMS

DES

BMS

No. patients

95

86

1 02

1 21

85

64

Follow-up

503 days

503 days

12 mo

30 mo

6 mo

6 mo

ACS (%)

52

50

59.8

67.8

30.9

42.1

Death (%)

14

16

0

0

3.5*

14.1

Nonfatal MI (%)

4*

12

6.9

8.3

7.1

7.8

TVR (%)

6*

23

2.0*

17.4

20

30.6

Any MACE

24*

45

2.0*

18.6

20.0*

35.9

Stent thrombosis (%)

nr

nr

0

0

1.2

0

Binary restenosis (%)

nr

nr

7.0

30.3

19.0

ACS, acute coronary syndromes; TVR, target vessel revascularization; MACE, major adverse cardiac event; MI, myocardial infarction; nr, not reported.

ACS, acute coronary syndromes; TVR, target vessel revascularization; MACE, major adverse cardiac event; MI, myocardial infarction; nr, not reported.

unprotected left main disease and historical control groups of 64 to 121 patients receiving bare metal stents.84-86 As shown in Table 6-4, the historical comparisons suggested that drug-eluting stents, compared with bare metal stents, reduced the risk of major adverse cardiac events during mid-term follow-up (6-12 months), a benefit that can be attributed largely to a reduction in the need for target vessel revascu-larization. This benefit prevailed after adjustment for differences in baseline characteristics between the respective study cohorts, which in general favored bare metal stents.

It is noteworthy that the incidence of severe complications such as cardiac death and MI was high, particularly in the series of Valgimigli and col-leagues.86 When interpreting these results, it must be taken into account that each of the registries included a large proportion of patients with acute coronary syndromes. The study of Valgimigli also included patients with acute ST-segment elevation MI and car-diogenic shock. In fact, seven of the deaths in the drug-eluting stent group of this study occurred in patients who presented with cardiogenic shock.

In the study of Park and associates, late lumen loss was lowest in the group of patients who could be treated with a single stent and highest in the group treated with the crushing technique.84 These observations are consistent with the findings of the combined analysis of the RESEARCH and T-SEARCH registries, which demonstrated a significantly elevated risk in patients with distal left main disease.87,88 In this analysis, the incidence of major adverse cardiac events during a median follow-up of 587 days was 30% in patients with distal left main disease versus 11% in those without. After adjustment for confounders and surgical risk status, distal left main disease remained a significant independent predictor of major adverse cardiac events (HR = 2.79; 95%-CI: 1.17 to 8.9; P = .032).

The registry data suggest a substantial benefit of drug-eluting stents versus bare metal stents but cannot assess the long-term risks, nor can they assess the efficacy compared with CABG. While randomized studies such as COMBAT and SYNTAX are underway, two nonrandomized studies comparing implantation of drug-eluting stents for unprotected left main disease with CABG have been published. The study by Lee and associates89 compared 50 patients who underwent PCI with drug-eluting stents for unprotected left main disease with 123 patients from the same institutions who underwent CABG. High-risk patients (Parsonett score >15) made up 46% of the CABG group and 64% of the PCI group (P = .04). Median follow-up was 6.7 months in the CABG group and 5.6 months in the PCI group. Freedom from major adverse cardiac and serious vascular events including death, MI, cerebrovascular events, and target vessel revascularization was 83% after CABG and 89% after PCI (P = .20). Freedom from death, MI, and cerebrovascular events at 6 months was significantly higher after PCI (95.6%) than after CABG (82.9%) (P = .03) (Fig. 6-10). By multivariable Cox regression analysis, CABG was an independent predictor of major adverse cardiovascular and cerebrovascular events.

Similar results were obtained in the study by Chieffo and colleagues.90 This study compared 107 patients with unprotected left main disease treated with PCI and drug-eluting stent implantation with 142 patients undergoing CABG. At 1 year, the rate of death, MI, and cerebrovascular events was significantly lower with PCI than with CABG (3.7% vs. 8.5%; P < .001). This difference prevailed after adjustment by propensity analysis with respect to baseline differences between the two cohorts (adjusted odds ratio = 0.39; 95% CI: 0.18 to 0.82; P = .01). On the other hand, there was a significant increase in target vessel revascularization in the PCI-treated patients (19.6% vs. 3.6%).

Although registry data and nonrandomized studies suggest a favorable outcome of PCI with drug-eluting stents for unprotected left main disease, they are far from being conclusive. Apart from the problems associated with the analysis of nonrandomized comparisons, the duration of follow-up is too short, and the number of patients included is too low to address the efficacy of drug-eluting stents with respect to survival.

Figure 6-10. Freedom from death, myocardial infarction, and cerebrovascular events in unprotected left main coronary artery disease after treatment with percutaneous coronary intervention (PCI) with drug-eluting stent implantation versus coronary artery bypass grafting (CABG). (From Lee MS, Kapoor N, Jamal F, et al: Comparison of coronary artery bypass surgery with percutaneous coronary intervention with drug-eluting stents for unprotected left main coronary artery disease. J Am Coll Cardiol 2006;47:864-870.)

ai CL

100 n

CABG PCI

CABG PCI

50 100 150 200 250 300 350 400 450 500 550 600 650

Days

Was this article helpful?

0 0
Your Heart and Nutrition

Your Heart and Nutrition

Prevention is better than a cure. Learn how to cherish your heart by taking the necessary means to keep it pumping healthily and steadily through your life.

Get My Free Ebook


Post a comment