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Complete coverage of long, diffuse lesions with ‘full metal jackets’ of drug-eluting stents (DES) provides acceptable long-term outcomes with 90% freedom from cardiac death out to 8 years, according to an observational study published online April 21, 2014, ahead of print in Catheterization and Cardiovascular Interventions. Left ventricular dysfunction and long stent length were found to predict major adverse events.

Seung-Jung Park, MD, PhD, of Asan Medical Center (Seoul, South Korea), and colleagues looked at long-term outcomes of 347 consecutive patients (352 lesions) treated for de novo diffuse CAD with full metal jacket stents (stent length ≥ 60 mm without gaps) at their institution between February 2003 and May 2005. Cypher (Cordis; Miami Lakes, FL) stents were implanted in three-quarters (75.6%) of lesions and Taxus devices (Boston Scientific; Natick, MA) in the remainder.

Procedural non-Q wave MI occurred in 19.6% of patients. During hospitalization, 3 patients (0.9%) experienced major complications: 1 death from cardiac tamponade immediately after the procedure and 2 cases of acute stent thrombosis and Q-wave MI 4 and 12 days after surgery.

Cardiac Death Low, TLR High

At a median follow-up of 101 months in 92.2% of patients, there were 60 deaths (33 cardiac), 20 MIs, and 94 revascularizations (64 TLRs). Academic Research Consortium-defined definite stent thrombosis occurred in 12 patients. Cumulative event-free survival was reasonable, although LV dysfunction and higher total stented length had a significant adverse impact. Rates of TLR and any revascularization were high (table 1).

Table 1. Cumulative Event-Free Survival at 8 Years

^aP < .001 for difference between LVEF ≥ vs < 45%.
^bP = .001 for difference between stented length ≤ vs > 80 mm.

Multivariate analysis identified 2 independent predictors of MACE:

• LVEF < 45% predicted cardiac death (OR 4.88; 95% CI 1.81-13.13; P = .002) and cardiac death/MI (OR 3.04; 95% CI 1.55-5.96; P = .001)
• Stent length > 80 mm predicted cardiac death/MI (OR 2.15; 95% CI 1.17-3.93; P = .014) and cardiac death/MI/TLR (OR 2.45; 95% CI 1.16-5.19; P = .019)

“These data… should further reassure clinicians that when [full metal jacket] stenting is deemed necessary, the hard outcomes of cardiac death and MI (about 2% per year for 8 years) are not an undue cause for concern,” wrote Andrew S. P. Sharp, MD, of Exeter Heart (Exeter, United Kingdom), in an email with TCTMD.

“TLR is again confirmed to be a potential consequence of such an approach, but in our experience the majority of such procedures involve focal segments of restenosis that are readily treated rather than extensive in-stent restenosis,” he added. “These [Korean] data support this concept, with a TLR rate of approximately 5% in the first year, followed by a steady 2% per year thereafter.”

‘Full Metal Jacket’ PCI a Clinical Call

“This is a large series with long-term follow-up, so these data are definitely useful,” Dimitrios Karmpaliotis, MD, PhD, of Columbia University Medical Center, told TCTMD in a telephone interview. He noted that the patients were treated at a very experienced center with high use of IVUS guidance, suggesting that stent deployment was optimal. Moreover, he pointed out, more than half of the procedures were performed in the LAD, where both stenting and surgical bypass tend to be more successful than in other vessels.

“Today, technically we can do very complex PCI in very complex lesions,” Dr. Karmpaliotis observed. However, he cautioned, the full metal jacket approach should be considered “in the context of the patient and the disease burden. We need to tailor therapy, and PCI and bypass are complementary strategies.” In addition, he noted, though the focus here is on mechanical revascularization, patients with extensive CAD and LV dysfunction need to be optimally medically managed, and unfortunately information on use of medications like statins and beta blockers is lacking in the paper.

Moreover, it would have been extremely useful had the investigators provided patients’ Syntax scores so that outcomes could be correlated with risk, he said, noting that almost three-quarters of the study cohort had multivessel disease. “That would put the data in the context of current knowledge on the best way to treat these patients,” he commented.

Dr. Karmpaliotis said the MACE predictors identified in the study—LV dysfunction and stent length > 80 mm—are of less use in guiding treatment choice than the authors suggest because they may be simply markers of sicker patients and not related to stenting. And given the observational nature of the study, it is impossible to know whether or not patients with these traits would have fared better with CABG, he added. However, a correlation between stent length and MACE is well established and should be taken into consideration, he noted.

In addition, it is unclear how many patients—if any—were “post CABG,” Dr. Karmpaliotis observed. Revascularization patterns differ markedly around the world, he said, with CABG being far more common in the United States than in Korea, for example. That is relevant, he explained, because in the United States, a large proportion of full metal jacket stenting is performed in diffusely diseased or totally occluded native arteries that had been supplied by now failed surgical grafts. In this scenario, PCI is technically more challenging and carries a far higher risk of restenosis than in other lesion subsets.

Would New-Generation, Bioresorbable DES Make a Difference?

As to whether use of newer DES might have improved outcomes, Dr. Karmpaliotis was cautious. “Second-generation stents are better designed,” he said, “but the improvements are only incremental.” Long-term studies in patients treated with a full metal jacket of newer DES are needed to prove their superiority to first-generation devices, he added.

Drs. Sharp and Karmpaliotis agreed that that question may be overshadowed by the advent of fully bioresorbable stents. “So-called ‘vascular restoration therapy’ offers an entirely new approach to diffuse disease, Dr. Sharp noted, which does not burn bridges with regard to future surgical bypass. In addition, “with increasingly sophisticated physiological guidance and intracoronary imaging, clinicians may find themselves able to take a more tailored approach to the treatment of long segments,” he concluded.

Study Details

Mean patient age was 61 years, and almost three-quarters (72.6%) were men. Overall, 57.9% had a history of hypertension, 36.3% had diabetes, 28.0% were current smokers, 74.1% had multivessel disease, and 10.4% had an LVEF < 45%.

The procedural success rate was 97.7%. The mean lesion length was 55.8 ± 12.9 mm, the number of stent overlaps per lesion was 2.5 ± 0.7, and the total stented length was 71.9 ± 13.7 mm. 

 

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Source:
Lee CW, Ahn J-M, Lee J-Y, et al. Long-term (8-year) outcomes and predictors of major adverse cardiac events after full metal jacket drug-eluting stent implantation. Catheter Cardiovasc Interv. 2014;Epub ahead of print.

 

• Drs. Park and Sharp report no relevant conflicts of interest.
• Dr. Karmpaliotis reports serving on the speaker’s bureau for Abbott, Asahi Intecc, Boston Scientific, and Medtronic.

 

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