Is refined OCT guidance of stent implantation needed?

The development of optical coherence tomography (OCT) provides new opportunities for the evaluation of coronary stents. Having a much higher spatial resolution than intravascular ultrasound (IVUS), OCT is currently used for long-term assessment of stent implantation. In the immediate future, however, it is quite likely that OCT will be used synergically with IVUS to optimise stent deployment; the criteria for optimising stent implantation using OCT will be clearly indebted to the evidence gathered with IVUS, with an added value in contexts like ambiguous images presenting after stenting, or in complex percutaneous coronary interventions (PCI) procedures like bifurcation stenting. However, since OCT is capable of identifying, during PCI, findings of potential relevance beyond the resolution IVUS, such as thrombus or tissue protrusion, intra-stent or edge dissections, or specific patterns of hyperplasia in restenotic lesions, it is foreseeable that new OCT-specific recommendations for optimal stent implantation will be made in the near future.

Evaluation of stents and grafts

In the management of patients with obstructive coronary artery disease (CAD), percutaneous coronary intervention (PCI) with stent implantation is routinely performed. In patients with left main or three-vessel disease, however, coronary artery bypass grafting (CABG) may be the preferred therapeutic strategy. Importantly, both after PCI or CABG a small but non-negligible risk of restenosis remains. Early detection and treatment of in-stent restenosis or graft disease is of great clinical importance. Accordingly, accurate non-invasive methods to identify patients who would benefit from subsequent invasive coronary angiography (ICA) would be highly beneficial. Besides ICA, several non-invasive cardiac imaging techniques may be used to assess patients after revascularisation. In the present article, an overview of various anatomic and functional imaging techniques available to assess patients after revascularisation is provided.

Retrograde approach to a totally occluded right coronary artery via a septal perforator artery: the tale of a long and winding wire

Retrograde recannalization of chronic total occlusions has developed as a viable alternative to restore coronary patency. Techniques continue to evolve and complications described. We present a new complication related to equipment developed to improve outcomes via a retrograde approach.

[Value of exercise electrocardiography and other current instrumental studies in the evaluation of percutaneous coronary interventions and in the detection of restenosis]

The current instrumental studies (graded exercise echocardiography (ECG)), exercise tests in combination with myocardial imaging (echocardiography, myocardial perfusion scintigraphy) used to evaluate restenosis after percutaneous coronary interventions (PCI) in patients with coronary heart disease are considered. The sensitivity, specificity, and prognostic value of these studies versus coronarography in the diagnosis of restenosis after PCI are given. The capabilities of other diagnostic techniques (ultrasound study of brachial artery dysfunction, intravascular ultrasound study of coronary arteries, multispiral computed tomography, etc.) are analyzed. It is emphasized that periodic use of exercise ECG tests after PCI has no advantages over their performance only on the basis of the clinical findings of the impact on quality of life, functional status, and clinical signs.

[Prospects for using non-invasive diagnostic techniques for assessment of cardiac rhythm variability in coronary restenosis]

The aim of the study was to evaluate dynamics of heart rhythm variability (HRV during a1, b1, and b2-adrenoblockade by carvedilol in patients with coronary heart disease (CHD) and recurrent angina pectoris treated by endovascular revascularization. The study included 39 men (mean age 57.5 +/- 0.8 years) who underwent stenting of coronary arteries (CA) 6 month or more before the study. For the purpose of analysis, patients with CA restenosis were allocated to group 1 (n = 17), those without restenosis or complaining of chest discomfort in the absence of restenosis during repeated coronaroventriculography comprised group 2 (n = 22). Patients having no complaints were followed up by coronarography 1 year after stenting. HRV was estimated from the analysis of short (15 min) fragments of the standard ECG obtained in the basal state and during a1, b1, b2-blockade by carvedilol (mean dose 22.88 +/- 2.1 mg/day) for 2 weeks. Carvedilol blockade of a1, b1, b2-adrenoreceptors following coronary stenting significantly improved both temporal and spectral components of HRV. This improvement may serve as an independent marker of revascularization efficiency and an earlier predictor of coronary restenosis or reflect progress of the atherosclerotic process in native arteries.

Blood platelet count and reactivity are associated with restenosis 6 months after coronary angioplasty

OBJECTIVES

Restenosis occurs in 40-50% of patients treated with percutaneous transluminal coronary angioplasty (PTCA). Some data indicate that platelet derived growth factor (PDGF) plays a pathogenetic role. The aims of the present study were to measure the plasma levels of PDGF across the coronary circulation during PTCA and relate them to the development of restenosis.

DESIGN AND RESULTS

Blood samples from the aortic root and coronary sinus were drawn simultaneously before, and after completed PTCA in 26 patients. Plasma levels of PDGF and beta-thromboglobulin (BTG), as well as platelet counts were measured. Restenosis was evaluated by quantitative coronary angiography after 6 months. Significant increases both in PDGF and BTG were encountered in the aortic root after PTCA in patients who developed restenosis as compared to patients without restenosis. Patients who developed restenosis also had significantly higher platelet counts compared to those without.

CONCLUSION

Increases in plasma PDGF and BTG in the aortic root after PTCA seem to be markers for restenosis 6 months after PTCA. This finding may strengthen the hypothesis that platelets contribute to the process of restenosis.

The clinical presentation of restenosis after bare metal stent implantation: behind a facade of benignity

Contrary to common belief, bare metal in-stent restenosis (ISR) seems to be not a benign clinical entity. Thus,we believed that continued efforts are warranted to prevent bare metal ISR, including aggressive use of drug-eluting stent (DES) to decrease the incidence of acute coronary syndromes. However, despite improved outcomes with DES, bare metal stent (BMS) will continue to play a role for both clinical and economic reasons and we feel that there is still a future for BMS.

Predictors of target lesion revascularization in patients undergoing lower extremity percutaneous interventions

BACKGROUND

Predictors of target lesion revascularization (TLR) have not been well defined in patients undergoing peripheral percutaneous interventions (PPI). In this study we analyze predictors of TLR in a consecutive cohort of patients from two medical centers.

METHODS

Data were extracted from a prospectively collected peripheral vascular registry. Of 105 consecutive patients (175 vessels) undergoing PPI, follow up was achieved in 104 patients (172 vessels) at 8.06 +/- 4.51 months. Univariate analysis was performed between the groups with (n = 19, vessels = 25) and without (n = 85, vessels = 147) TLR. Logistic regression analysis was utilized to model for the predictors of TLR.

RESULTS

TLR occurred in 14% of vessels treated at 8.06 +/- 4.51 months. By univariate analysis, vessels with TLR on follow up had longer treated segments (167.0 +/- 139.16 mm vs. 98.49 +/- 113.33 mm; p = 0.027), more severe lesions (91.96 +/- 12.56% vs. 85.51 +/- 14.43%; p = 0.037) and were younger (63.0 +/- 10.1 years vs. 69.1 +/- 11.1 years; p = 0.032). Also, there was a trend toward a higher hs-CRP (11.35 +/- 17.85 vs. 7.45 +/- 9.57 mg/L) and more total occlusions (44.0% vs. 22.6%) in the TLR group, but these did not reach statistical significance. Logistic regression analysis with backward elimination including all these variables showed that younger age (p = 0.007), female gender (p = 0.033) and treated vessel length (p = 0.028) were the only independent predictors of TLR.

CONCLUSIONS

Younger age, female gender and longer treated vessel length are independent predictors of TLR in patients undergoing PPI. The cost-effectiveness in treating these patients with PPI versus surgery needs to be defined in future studies.

Treatment of patients with in-stent restenosis

Treatment of patients with in-stent restenosis (ISR) remains a technical challenge. This problem has been reduced since the advent of drug-eluting stents (DES), but continues to represent a significant burden during daily practice in interventional cardiology. Treatment of ISR after bare-metal stent implantation has evolved and currently DES constitute the intervention of choice. However, DES may also develop ISR. The best therapeutic alternative for patients suffering from ISR after DES implantation remains to be elucidated. This review will focus on treatment of patients with ISR emphasising currently available alternatives, technical issues, limitations and future perspectives.

Meditations on secondary revascularisation in the aftermath of the SYNTAX trial

Many patients will experience a return of symptoms after their initial revascularisation procedure necessitating secondary revascularisation (SR). The options for this second procedure are inherently influenced by the primary method adopted for revascularisation. Patients with single vessel disease are most suited to percutaneous coronary intervention (PCI) for both primary and secondary revascularisation. The arrival of drug eluting stents, and evidence from trials of highly select populations has threatened the place of coronary artery bypass grafting (CABG) as the preferred method of revascularisation in those with multivessel disease. At present, and without robust evidence, PCI is increasingly being used to treat highly complex lesions, such that many question whether CABG is still has a role in primary revascularisation. The consequence for SR is that currently it is increasingly likely to be in response to in-stent restenosis, whereby previously it was performed in those with prior CABG. The recent SYNTAX trial has reaffirmed the position of CABG in the treatment of those with complex coronary disease. Consequently we believe that matters have turned a full circle, and expect that SR in the future is most likely to be in form of PCI on patients 8-15 years post primary CABG.

Secondary coronary revascularisation: an emerging issue

Coronary revascularisation should be considered as a healthcare process rather than a series of episodic interventions. At a time when the number of surgical and interventional procedures worldwide continues to increase, secondary coronary revascularisation appears as an unavoidable subject. Atherosclerosis progression, long-term failure of surgical grafts or stents, and patient profile contribute to the increased risk of secondary revascularisation. The absence of a grouping category, however, has contributed to suboptimal implementation of evidence-based knowledge on the subject, which is scattered in the literature and scantily covered in clinical practice guidelines. Assembling a critical mass of expertise in the field results mandatory for comprehensive patient management and for highlighting avenues for future research. Knowledge sharing between physicians, interventionalists and surgeons appears indispensable to reduce unilateral decision-making. Awareness of all health professionals about the likelihood of repeated revascularisation appears as the first step towards a process-oriented and holistic management of patients requiring coronary revascularisation.

Digital enhancement of stent images in primary and secondary percutaneous coronary revascularisation

Inadequate stent expansion and apposition during percutaneous coronary intervention increases the risk of subsequent restenosis and thrombosis. In repeat and complex percutaneous interventions, such as treatment of stent restenosis or bifurcation techniques, these aspects present a renewed importance. Intravascular ultrasound (IVUS) constitutes the standard technique to assess stent expansion, but its use in clinical practice is far from being universal. Although most current stent designs are radiolucent, new radiological imaging modalities, specifically tailored to coronary stent imaging, can render images with enough quality to visualise stent sub-expansion. While this approach might be complementary to IVUS in clinical practice, few in vivo studies comparing both techniques are available. In this article we review the principles of digital enhancement of stent images and the available validation studies. Furthermore, we report on a comparison between IVUS and digital enhancement stent images performed after coronary stenting.

Impact of female gender and transradial coronary stenting with maximal antiplatelet therapy on bleeding and ischemic outcomes

BACKGROUND

Female gender has been associated with poorer outcomes after percutaneous coronary intervention (PCI) and femoral approach. However, no data are available on the impact of gender and transradial PCI with maximal antiplatelet therapy on bleeding and ischemic outcomes.

METHODS

In the EArly discharge after Stenting of coronarY arteries (EASY) trial, 1,348 patients with acute coronary syndrome underwent transradial PCI. All patients were pretreated with aspirin and clopidogrel. After sheath insertion, 70 U/kg heparin was administered and a bolus of abciximab was given before first balloon inflation. Major adverse cardiac events including death, myocardial infarction, and target vessel revascularization; major bleeding; and local hematomas were evaluated at 30 days, 6 months, and 12 months.

RESULTS

Women (n = 298, 22%) were older, had more hypertension, more family history, and less previous PCI than men. Weight, baseline hemoglobin, and creatinine clearance were significantly lower in women. The number of dilated sites, complex lesions, and procedure duration was similar, but 5F sheath size was more frequent in women. Major adverse cardiac events remained similar at 30 days (3.4% vs 3.9%, P = .86), at 6 months (11.5% vs 7.8%, P = .06), and at 1 year (14.1% vs 12.6%) in both groups. There was no significant difference in the incidence of major bleeding between the 2 groups, but female gender was the only independent predictor of hematomas (odds ratio 4.40, 95% confidence interval 2.49-7.81, P < .0001).

CONCLUSION

Despite more comorbidities, female gender was not a predictor of adverse clinical outcomes after transradial PCI with maximal antiplatelet therapy. Still, female gender remained associated with a higher risk of local hematomas. Efforts should continue to identify modifiable factors to reduce procedural bleeding in women, regardless of the access site.

Long-term follow-up after deferring angioplasty in asymptomatic patients with moderate noncritical in-stent restenosis

BACKGROUND

Many patients with in-stent restenosis (ISR) are angina-free, but the optimal treatment for these patients remains uncertain.

HYPOTHESIS

In cases with asymptomatic moderate noncritical ISR. deferral of the intervention may be safe and associated with favorable clinical outcome.

METHODS

We evaluated the long-term clinical outcome of asymptomatic patients (Group 1, n = 98) with moderate noncritical ISR (< 70% diameter stenosis) after intervention was deferred, and compared it with that of patients (Group 2, n = 655) without restenosis. After repeat angioplasty was deferred, all patients were treated medically and later underwent angioplasty only in the case of clinical recurrence.

RESULTS

Baseline characteristics were similar between the two groups. Clinical follow-up was available in all patients at 26.3+/-15.9 months. Twenty patients died during the follow-up: 1 in Group 1 and 19 in Group 2. Target lesion revascularization was performed in 3 patients in Group 1 and 11 patients in Group 2 during follow-up (p = NS), and new lesion revascularization in 2 patients in Group 1 and 27 patients in Group 2 (p = NS). Event-free survival rate (cardiac death, nonfatal myocardial infarction, repeat revascularization) was 86.7+/-6.1% in Group 1 and 84.8+/-2.2% in Group 2 at the end of follow-up (p = NS). Major adverse cardiac events were only associated with the presence of diabetic mellitus (hazards ratio 2.65, 95% confidence interval [CI] 1.48-4.73, p<0.01). The percentage of patients receiving antianginal medication was similar between the two groups at the end of the study (p = NS).

CONCLUSIONS

Asymptomatic patients with moderate noncritical ISR have a good prognosis and similar clinical outcome as those without ISR, suggesting that it may be safe to defer repeat angioplasty in these patients until angina recurrence.

A simple ECG marker for the detection of coronary restenosis after successful coronary angioplasty

BACKGROUND

The dynamic nature of QT dispersion (QTd) and the absence of an acceptable normal value suggest that the relative change not the absolute value of QTd would be a better predicator of coronary restenosis. We sought to examine the usefulness of the relative change in QTd, compared to the absolute value, as a predictor for coronary restenosis after previously successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Ninety-two patients with a history of successful PTCA who were referred for coronary angiography (CA) for exclusion of coronary restenosis were included in this analysis. QTd was calculated as the difference in milliseconds between the maximum and minimum QT interval in the 12-lead ECG. Relative change in QTd was measured as [QTd at the time of angiography (current) - QTd after the successful PTCA (baseline)]/QTd (baseline) %. Receiver operating characteristics (ROC) analysis was used to detect the best cut-off point and also to compare the diagnostic accuracy of the relative change in QTd vs. the absolute QTd for prediction of coronary restenosis.

RESULTS

The relative change in QTd showed a significantly larger ROC area under curve (AUC) compared to the absolute QTd [AUC (95% CI): 0.79 (0.698, 0.872) and 0.61 (0.498, 0.703) respectively; p=0.011 for AUCs comparison]. The best cut-off point for the relative QTd was 40%, and for the absolute QTd this was 50 ms. The sensitivity and specificity of > or =40% increase in QTd to detect coronary restenosis was 71% and 83%, with positive and negative predictive values of 90% and 57%, respectively. The diagnostic accuracy of the absolute value of QTd was much less than this; the sensitivity and specificity of QTd > or =50 ms were 48% and 58%, with positive and negative predictive values of 71% and 34%, respectively.

CONCLUSIONS

Compared to the absolute value, the relative change in QTd is a better predictor of coronary restenosis after a previously successful PTCA. These findings may open the door for rethinking the use of QTd as a simple ECG predictor for cardiovascular outcomes.

[Clinical application of 64-slice CT angiography in the evaluation of lumen before and after coronary artery stent implantation]

This is a retrospective study aimed at the clinical application of 64-slice computed tomography angiography (CTA) in evaluation the lumen before and after coronary artery stent implantation. We collected the coronary artery imaging data of 46 patients undergoing 64-slice CT before coronary artery stent implantation from July 2006 through May 2007; we also collected the data of 21 patients with 34 coronary artery stents in the same period to determine the diagnostic accuracy of CTA before and after coronary artery stent implantation. The results showed that, in 46 patients, 64-slice CT enabled the visualization of the entire coronary tree with diagnostic image quality. Sensitivity, specificity, and accuracy for the detection of stenosis > or = 50% were 92.11%, 95.64% and 94.97%, respectively. In 21 patients with 34 stents implanted, 23 (67.65%) stents showed no stenosis, 8 (23.53%) stents showed low degree of restenosis, and 3 (8.83%) stents showed high degree of restenosis. In conclusion, we can accurately evaluate the degree of stenosis of lumen before and after coronary artery stent implantation with the application of 64-slice CTA.

"Black hole" restenosis after sirolimus-eluting stent implantation

In several reports, the "black hole" (BH) phenomenon was reported as a homogeneous echolucent appearance by intravascular ultrasound. We discuss an experience with angioscopic and pathological assessment for the BH phenomenon.

Coexistent in-stent restenosis, late incomplete stent apposition and mural thrombus in a zotarolimus-eluting stent

Drug-eluting stents (DES) have been demonstrated to dramatically reduce the rate of in-stent restenosis (ISR). However, some studies found an increased rate of late incomplete stent apposition (ISA) and late stent thrombosis (ST) in DES compared to traditional bare-metal stents (BMS). Endeavor stent, a new cobalt-alloy DES coated with phosphorylcholine and zotarolimus, has been reported to have a very favorable safety profile with few documented late-acquired ISA and late ST. In the present report, we described an interesting case with coexistent ISR, late ISA and mural thrombus in an Endeavor zotarolimus-eluting stent 8 months after primary percutaneous coronary intervention.

Accuracy of 64-slice coronary CT angiography in predicting percentage diameter stenosis

OBJECTIVE

Aim of our study was to evaluate the diagnostic accuracy of 64-slice CT coronary angiogram in measuring the percentage diameter stenosis compared to invasive angiography.

METHODS AND RESULTS

100 consecutive patients with more than 50% stenosis in at least one major coronary artery measured by 64-slice CT angiogram were included in the study. Patients with atrial fibrillation, history of allergy to contrast agent, acute coronary syndrome, renal insufficiency, history of previous coronary bypass surgery or percutaneous transluminal coronary stent, heart rate more than 70 per minute at the time of scan in spite of beta-blocker therapy, and calcium score >2000 Agaston units were not included in the study. 15-segment American Heart Association classification was used, and segments were compared using qualitative angiography. 192 segments (12.80%) could not be assessed due to poor image quality. The major cause for poor image quality was dense calcification precluding the luminal assessment (60.42%). Comparing the maximal percentage diameter stenosis by 64-slice CT versus invasive angiogram, the Spearman correlation coefficient between the two modalities was 0.788 and p value was <0.001. Bland-Altman analysis showed a mean difference in percentage stenosis of 2.1 +/- 16.22%. A total of 91.97% (401 of 436) of segments were within 1.96 standard deviations.

CONCLUSION

This study shows that 64-slice CT coronary angiogram is accurate in detecting percentage diameter stenosis compared to coronary angiogram if the image quality is good. Calcifications and motion artifacts are the main culprits of poor image quality.

In-hospital and late clinical outcomes of direct stenting strategy versus stenting after predilatation for the treatment of coronary artery lesions

BACKGROUND

Direct stenting without balloon dilatation may reduce procedural costs and duration, and hypothetically, the restenosis rate. This study was designed to compare the in-hospital and long-term outcomes of direct stenting (DS) versus stenting after predilatation (PS) in our routine clinical practice.

METHODS

One thousand six hundred and three patients treated with stenting for single coronary lesions were enrolled into a prospective registry. Patients with acute myocardial infarction (MI) within the preceding 48 hours, highly calcified lesions, total occlusions, or lesion in a saphenous graft were excluded. The baseline, angiographic, and procedural data, in-hospital outcomes and follow-up data were recorded in our database, and analyzed with appropriate statistical methods.

RESULTS

Eight hundred and fifty-seven patients (53.5%) were treated with DS, whereas 746 of them (46.5%) underwent PS. In the DS group, lesions were shorter in length, larger in diameter, and had lower pre-procedural diameter stenosis. Type C and diffuse lesions and drug-eluting stents were less frequent (p < 0.001). In univariate analysis, dissection and non-Q-wave MI occurred less frequently in this group (0.2% and 0.6% vs 3.9% and 2.1%, p < 0.001 and p 7 = 0.01, respectively). However, the cumulative major adverse cardiac events (MACE) did not differ significantly (4.9% vs 4.6%, p = 0.79). In multivariate analysis, direct stenting reduced the risk of dissection (OR = 0.07, 95% CI: 0.01-0.33), but, neither the cumulative endpoint of MACE (OR = 1.1, 95% CI = 0.58-2.11, p = 0.7) nor its constructing components were different between the groups.

CONCLUSIONS

Direct stenting in real world has at least similar long-term outcomes with patients treated with stenting after predilatation and is associated with lower dissection rate.

Transcatheter coil occlusion of a side branch of the left internal mammary artery graft causing significant ischaemia

Coronary steal due to an unligated side branch of the internal mammary artery graft is a rare but important pathology causing ischaemia. We describe the case of a patient with significant ischaemia having an unligated side branch of the left internal mammary artery after coronary artery bypass surgery and who underwent coil embolization of the side branch.