Increased CK-MB release is a “trade-off” for optimal stent implantation

Impact of post-dilatation on post-procedural physiology, microcirculatory resistance, and target vessel failure in STEMI patients undergoing PPCI: A single-center experience

BACKGROUND

Suboptimal stent deployment is frequently observed in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). This study sought to investigate whether these patients could benefit from post-dilatation with respect to post-procedural physiology, microcirculatory resistance, and long-term clinical outcomes.

METHODS

This was a retrospective study of consecutive STEMI patients who underwent successful stent implantation during PPCI from February 2016 to November 2021. Post-procedural physiology and microcirculatory resistance were assessed by Murray law-based quantitative flow ratio (μQFR) and angiographic microcirculatory resistance (AMR), respectively. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel-oriented myocardial infarction, and clinically driven target vessel revascularization.

RESULTS

A total of 671 patients (671 culprit vessels) were included. Post-dilatation was selectively performed in 430 (64.1%) culprit vessels, resulting in a 0.02 (interquartile range: 0.00-0.05, p < 0.001) increase in post-procedural μQFR but no significant impact on AMR. During a median follow-up of 2.8 years (interquartile range: 1.4-3.0 years), TVF occurred in 47 (7.0%) patients. Post-dilatation demonstrated a trend toward a reduction in TVF (5.3% vs. 10.0%; adjusted hazard ratio: 0.60, 95% confidence interval: 0.33-1.09, p = 0.094), mainly driven by a lower incidence of clinically driven target vessel revascularization (1.6% vs. 4.1%; adjusted hazard ratio: 0.32, 95% confidence interval: 0.11-0.90, p = 0.030).

CONCLUSIONS

In STEMI patients undergoing PPCI, selective post-dilatation was associated with improved post-procedural physiological results and a trend toward less TVF events without aggravating microcirculatory resistance.

Prognostic and diagnostic accuracy of intracoronary electrocardiogram recorded during percutaneous coronary intervention: a meta-analysis

OBJECTIVE

Intracoronary ECG (IC-ECG) recording has been shown to be sensitive and reliable for detecting myocardial viability and local myocardial ischaemia in some studies. But IC-ECG is neither widely used during percutaneous coronary intervention (PCI) nor recommended in guidelines. This up-to-date meta-analysis of published studies was conducted to evaluate the prognostic and diagnostic accuracy of IC-ECG recorded during PCI.

METHODS

Relevant studies were identified by searches of MEDLINE until 19 June 2021. Observational and diagnostic studies which reported the prognostic or diagnostic accuracy of IC-ECG were included. Data were extracted independently by two authors. Summary estimates of clinical outcomes were obtained using a random effects model. Summary diagnostic accuracy was obtained by using a Bayesian bivariate random effects model.

RESULTS

Of the 12 included studies, 7 studies reported the clinical outcomes (821 patients) and 6 studies reported the diagnostic accuracy (485 patients) of IC-ECG. The pooled ORs with 95% CIs of ST-segment elevation recorded by IC-ECG were 4.65 (1.69 to 12.77), 5.08 (1.10 to 23.44), 4.53 (0.79 to 25.90) and 1.83 (0.93 to 3.62) for major adverse cardiac events, myocardial infarction, cardiac death and revascularisation, respectively. The weighted mean difference were 6.49 (95% CIs 3.84 to 9.14) for ejection fraction when ST-segment resolution was recorded, and 0.86 (95% CIs -8.55 to 10.26) when ST-segment elevation was recorded. The pooled sensitivity and specificity of ST-segment elevation were 0.78 (95% credibility intervals 0.64 to 0.89) and 0.87 (95% credibility intervals 0.75 to 0.94), respectively.

CONCLUSIONS

These findings provide quantitative data supporting that IC-ECG had promising diagnostic ability for local myocardial injury, and could predict clinical outcomes.

The Effects of Ticagrelor Combined with Tirofiban on Coagulation Function, Serum Myocardial Injury Markers, and Inflammatory Factor Levels in Patients with Acute Myocardial Infarction after Percutaneous Coronary Intervention

Background

Acute myocardial infarction (AMI) refers to the acute necrosis of part of the myocardium caused by persistent and severe myocardial ischemia. This study is aimed at investigating the efficacy of tirofiban combined with ticagrelor in AMI patients after percutaneous coronary intervention (PCI) and its effects on plasma activated partial thromboplastin time (APTT), fibrinogen (FIB), D-dimer (D-D) levels, myocardial injury markers, and inflammatory factors.

Methods

68 AMI patients with AMI who received PCI were divided into control group and observation group (n =34) according to postoperative treatment methods. Both groups received ticagrelor tablets (90 mg). The observation group was additionally given tirofiban (10 μg/kg). APTT, FIB, D-D, serum myoglobin (MB), cardiac troponin I (cTnI), serum C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and IL-6, myeloperoxidase (MPO) levels and the peak time in both groups were detected. The incidence of cardiovascular events and drug safety were compared.

Results

After treatment, APTT was increased, and FIB and D-D levels were decreased in both groups. After treatment, the APTT in the observation group was longer, and FIB and D-D levels were lower than those in the control group. The peak time of serum MB and cTnI in the observation group was earlier than that in the control group. The levels of serum MB and cTnI in the observation group were lower than those in the control group. After treatment, serum CRP, TNF-α, IL-6, and MPO levels were decreased. And the incidence of cardiovascular events was reduced.

Conclusion

Tirofiban combined with ticagrelor can improve coagulation function, protect myocardium, relieve inflammation, and reduce the risk of cardiovascular events in patients with AMI after PCI.

The Clinical and Angiographic Outcomes of Postdilation after Percutaneous Coronary Intervention in Patients with Acute Coronary Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The effect of postdilation in patients with acute coronary syndrome is still controversial. This meta-analysis aims to analyze the clinical and angiographic outcomes of postdilation after percutaneous coronary intervention in patients with acute coronary syndrome.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science, CNKI, and Wangfang databases were searched from inception to August 30, 2020. Eligible studies from acute coronary syndrome patients treated with postdilation were included. The primary clinical outcome was major adverse cardiovascular events (MACE), the secondary clinical outcomes comprised all-cause death, stent thrombosis, myocardial infarction, and target vessel revascularization, and the angiographic outcomes were no reflow and slow reflow.

RESULTS

11 studies met inclusion criteria. In clinical outcomes, our pooled analysis demonstrated that the postdilation had a tendency of decreasing MACE (OR = 0.67, 95% CI 0.45-1.00; P = 0.05) but significantly increased all-cause death (OR = 1.49, 95% CI 1.05-2.12; P = 0.03). No significant difference existed in stent thrombosis (OR = 0.71, 95% CI 0.40-1.26; P = 0.24), myocardial infarction (OR = 1.40, 95% CI 0.51-3.83; P = 0.51), and target vessel revascularization (OR = 0.61, 95% CI 0.21-1.80; P = 0.37) between postdilation and non-postdilation groups. In angiographic outcomes, there were no significant differences in no reflow (OR = 1.19, 95% CI 0.54-2.65; P = 0.66) and slow reflow (OR = 1.12, 95% CI 0.93-1.35; P = 0.24) between two groups.

CONCLUSIONS

The postdilation tends to reduce the risk of MACE but significantly increases all-cause death, without significantly affecting stent thrombosis, myocardial infarction, target vessel revascularization, and coronary TIMI flow grade. However, more randomized controlled trials are required for investigating the effect of postdilation for patients with acute coronary syndrome (registered by PROSPERO, CRD42020160748).

Additional postdilatation using noncompliant balloons after everolimus-eluting stent implantation: Results of the PRESS trial

Background

There are limited data on the clinical value of routine postdilatation using noncompliant balloons after contemporary drug‐eluting stent implantation.

Hypothesis

Additional postdilatation using noncompliant balloons after everolimus‐eluting stent implantation could provide better clinical outcomes.

Methods

We randomly assigned 1774 patients with coronary artery disease to undergo additional high‐pressure postdilatation using noncompliant balloons and moderate‐pressure dilatation using stent balloons after everolimus‐eluting stent implantation. The primary endpoint was a composite of death, myocardial infarction (MI), stent thrombosis, and target vessel revascularization (TVR) 2 years after randomization.

Results

The study was discontinued early owing to slow enrollment. In total, 810 patients (406 patients in the high pressure group and 404 in the moderate pressure group) were finally enrolled. At 2 years, the primary endpoint occurred in 3.6% of patients in the high pressure group and in 4.4% of those in the moderate pressure group (P = .537). In addition, no significant differences were observed between the two groups in the occurrence of an individual end point of death (0.8% in the high pressure group vs 1.5% in the moderate group, P = .304), MI (0.2% vs 0.5%, P = .554), stent thrombosis (0% vs 0.2%, P = .316), or TVR (2.8% vs 2.6%, P = .880).

Conclusions

The strategy of routine postdilatation using noncompliant balloons after everolimus‐eluting stent implantation did not provide incremental clinical benefits.

Post-dilatation improves stent apposition in patients with ST-segment elevation myocardial infarction receiving primary percutaneous intervention: A multicenter, randomized controlled trial using optical coherence tomography

BACKGROUND

Stent failure is more likely in the lipid rich and thrombus laden culprit lesions underlying ST-segment elevation myocardial infarction (STEMI). This study assessed the effectiveness of post-dilatation in primary percutaneous coronary intervention (pPCI) for acute STEMI.

METHODS

The multi-center POST-STEMI trial enrolled 41 consecutive STEMI patients with symptom onset <12 hours undergoing manual thrombus aspiration and Promus Element stent implantation. Patients were randomly assigned to control group (n=20) or post-dilatation group (n=21) in which a non-compliant balloon was inflated to >16 atm pressure. Strut apposition and coverage were evaluated by optical coherence tomography (OCT) after intracoronary verapamil administration via thrombus aspiration catheter, post pPCI and at 7-month follow-up. The primary endpoint was rate of incomplete strut apposition (ISA) at 7 months after pPCI.

RESULTS

There were similar baseline characteristics except for stent length (21.9 [SD 6.5] mm vs. 26.0 [SD 5.8] mm, respectively, P=0.03). In post-dilatation vs. control group, ISA rate was lower (2.5% vs. 4.5%, P=0.04) immediately after pPCI without affecting final TIMI flow 3 rate (95.2% vs. 95.0%, P>0.05) or corrected TIMI frame counts (22.6±9.4 vs. 22.0±9.7, P>0.05); and at 7-month follow-up (0.7% vs. 1.8%, P<0.0001), the primary study endpoint, with similar strut coverage (98.5% vs. 98.4%, P=0.63) and 1-year rate of major adverse cardiovascular events (MACE).

CONCLUSION

In STEMI patients, post-dilatation after stent implantation and thrombus aspiration improved strut apposition up to 7 months without affecting coronary blood flow or 1-year MACE rate. Larger and longer term studies are warranted to further assess safety (ClinicalTrials.gov identifier: NCT02121223).

Periprocedural Myocardial Infarction in Contemporary Practice

"Periprocedural myocardial infarction (MI) occurs infrequently in the current era of percutaneous coronary interventions (PCI) and is associated with an increased risk of mortality and morbidity. Periprocedural MI can occur due to acute side branch occlusion, distal embolization, slow flow or no reflow phenomenon, abrupt vessel closure, and nonidentifiable mechanical processes. Therapeutic strategies to reduce the risk of periprocedural MI include dual antiplatelet therapy, intravenous cangrelor in the periprocedural setting, intravenous glycoprotein IIb/IIIa inhibitor in high-risk patients, anticoagulation with unfractionated heparin, low-molecular-weight heparin or bivalirudin, and embolic protection devices during saphenous vein graft interventions."

Effect of Post-Dilatation Following Primary PCI With Everolimus-Eluting Bioresorbable Scaffold Versus Everolimus-Eluting Metallic Stent Implantation: An Angiographic and Optical Coherence Tomography TROFI II Substudy

OBJECTIVES

This study sought to investigate the effect of post-dilatation on angiographic and intracoronary imaging parameters in the setting of primary percutaneous coronary intervention comparing the everolimus-eluting bioresorbable scaffold (BRS) with the everolimus-eluting metallic stent (EES).

BACKGROUND

Routine post-dilatation of BRS has been suggested to improve post-procedural angiographic and subsequent device-related clinical outcomes.

METHODS

In the ABSORB STEMI TROFI II trial, 191 patients with ST-segment elevation myocardial infarction were randomly assigned to treatment with BRS (n = 95) or EES (n = 96). Minimal lumen area and healing score as assessed by optical coherence tomography at 6 months were compared between BRS- and EES-treated patients stratified according to post-dilatation status.

RESULTS

Primary percutaneous coronary intervention with post-dilatation was performed in 48 (50.5%) BRS- and 25 (25.5%) EES-treated lesions. There were no differences in baseline characteristics and post-procedural minimal lumen diameter between groups. In the BRS group, lesions with post-dilatation were associated with a trend toward a smaller minimal lumen area at 6 months (5.07 ± 1.68 mm² vs. 5.72 ± 1.77 mm²; p = 0.09) and significantly larger angiographic late lumen loss (0.28 ± 0.34 mm vs. 0.12 ± 0.25 mm; p = 0.02), whereas no difference was observed in the EES arm (5.46 ± 2.18 mm² vs. 5.55 ± 1.77 mm²; p = 0.85). The neointimal healing score was low and comparable between groups with and without post-dilation (BRS: 1.55 ± 2.61 vs. 1.92 ± 2.17; p = 0.48; EES: 2.50 ± 3.33 vs. 2.90 ± 4.80; p = 0.72).

CONCLUSIONS

In the setting of selected patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention with BRS or EES, post-dilatation did not translate into larger lumen area or improved arterial healing at follow-up. (ABSORB STEMI: The TROFI II; NCT01986803).

Predictive value of plaque morphology assessed by frequency-domain optical coherence tomography for impaired microvascular perfusion after elective stent implantation: the intracoronary electrocardiogram study

Aims

This study was undertaken to assess the association between plaque features at culprit lesions assessed by frequency-domain optical coherence tomography (FD-OCT) and impaired microvascular perfusion estimated by intracoronary electrocardiogram (IcECG) after elective percutaneous coronary intervention (PCI). Furthermore, we investigated whether IcECG could predict future cardiac events.

Methods and results

This study consisted of 84 patients who underwent both FD-OCT and IcECG during PCI. Patients were classified into two groups based on ST-segment elevation (ST-E) on IcECG after the procedure; ST-E (-) group (n = 53) and ST-E (+) group (n = 31). Minimum fibrous cap thickness was significantly thinner in the ST-E (+) group than in the ST-E (-) group (240 μm [IQR 180 to 310] vs. 100 μm [IQR 60 to 120], P < 0.001). Plaque rupture (7.5% vs. 35.5%, P = 0.001), lipid-rich plaque (75.5% vs. 100%, P < 0.001), the thin cap fibroatheroma (0% vs. 25.8%, P < 0.001) on pre-FD-OCT, protrusion (18.9% vs. 56.7%, P < 0.001), and intra-stent dissection (15.1% vs. 50.0%, P < 0.001) on post-FD-OCT were significantly more frequently found in the ST-E (+) group than in the ST-E (-) group. The incidence of MACE (cardiac death, myocardial infarction, revascularization, hospitalization for heart failure) during 1-year was significantly higher in the ST-E (+) group than in the ST-E (-) group (5.7% vs. 19.4%, P < 0.05).

Conclusion

Plaque features assessed by FD-OCT might be associated with impaired microvascular perfusion and ST-segment elevation on IcECG after the procedure could predict 1-year cardiac events after elective PCI.

Effect of Adjunct Balloon Dilation after Long Everolimus-eluting Stent Deployment on Major Adverse Cardiac Events

Background and Objectives

The effectiveness of adjunct balloon dilation after drug-eluting stent (DES) deployment has not been sufficiently evaluated. We evaluated whether adjunct balloon dilation was associated with a reduction in major adverse cardiac events (MACEs) after long everolimus-eluting stents (EESs) implantation.

Subjects and Methods

Drawing from 2 randomized trials, a total of 1,672 patients treated with long EES were analyzed. Of 1,672 patients, 1,061 patients (64%) received post-stent adjunct balloon dilation. MACE, defined as a composite of cardiac death, myocardial infarction, and target-lesion revascularization (TLR), was compared between patients who received post-stent adjunct balloon dilation and patients who did not in 595 propensity score-matched pairs.

Results

For the matched population, MACE occurred in 29 patients (4.9%) who received adjunct balloon dilation and in 29 patients (4.9%) who did not (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.60–1.69; p=0.972). However, significant interactions were observed among the subgroups for clinical presentation and vessel size. Adjunct balloon dilation was more favored within the subset of patients with stable angina vs. the subset of patients with acute coronary syndrome (p for interaction=0.037), and within the subset of lesions with small vessel diameter (reference vessel diameter [RVD] <3 mm) vs. the subset of lesions with larger vessel diameter (RVD ≥3 mm; p for interaction=0.027).

Conclusion

Adjunct balloon dilation was not associated with MACE reduction at 1 year among patients requiring long EES implantation. However, post-stent adjunct balloon dilation may be necessary for patients requiring long EES implantation who present with stable angina or for lesions with small vessel diameters.

Ten Years of Advancements in Interventional Cardiology

The past decade has seen the evolution of an exciting technology that has changed forever the treatment of aortic aneurysmal disease. From rather crude homemade stent-grafts constructed in the surgical suite to elegant commercially manufactured devices in a variety of configurations and sizes, the aortic endograft has experienced a meteoric rise in popularity to become a beneficial, minimally invasive therapy that can obviate the risk of rupture and death. There are now 3 approved endovascular devices on the market for infrarenal abdominal aortic aneurysm repair, and it is likely that additional and improved devices will become available in the future. This review revisits the developmental history of the aortic endograft, noting the ongoing refinements that have arisen from our experiences with the growing population of stent-graft patients. Although research continues to search for solutions to the problems of endoleak and migration, long-term results even with the earlier second and third-generation devices are better than has been achieved with open surgical repair.

Embolization after percutaneous coronary intervention in acute coronary syndrome. Saphenous vein grafts versus native coronary arteries

AIMS

The aim of this study was to assess the occurrence of distal embolization and to quantify the amount of embolic material captured during stent implantation in native coronary arteries, as compared with saphenous vein grafts (SVG) in patients at different time periods after an acute coronary syndrome.

PATIENTS AND METHODS

In all, 104 patients presenting with unstable or stable angina underwent percutaneous coronary intervention (PCI) in 107 vessels and stent implantation in 112 lesions, 53 % of which were in SVG.

RESULTS

Device deployment and retrieval was successful in 111 lesions. Embolic material was detected in 74 % of the protection devices. Early PCI, during a 2-week period after the last ischemic episode, was associated with larger embolic load, especially in the right coronary artery. The length of the lesion was the only preprocedural independent variable that was found to be a significant predictor for the presence of emboli (p = 0.002). The stent diameter and the maximum dilatation pressure were the two procedural variables found to be significant predictors for the presence of emboli (p = 0.025 and p = 0.008, respectively). The irregularity of the lesion and the number of stents deployed were found to have a predictive correlation to the total area of the embolic particles (p = 0.04 and p = 0.005, respectively).

CONCLUSION

Distal embolization of atherosclerotic debris is a frequent phenomenon after PCI not only in SVG but also in native vessels. The amount of embolic material seems to be related to the atherosclerotic burden of the vessel and to the early timing of the procedure as related to acute coronary syndrome.

Positive association of coronary calcium detected by computed tomography coronary angiography with periprocedural myocardial infarction

BACKGROUND

Periprocedural myocardial infarction (PMI) may occur in approximately 5% to 30% of patients undergoing percutaneous coronary intervention. Whether the morphology of coronary plaque calcium affects the occurrence of PMI is unknown.

MATERIALS AND METHODS

A total of 616 subjects with stable angina and normal baseline cardiac troponin I levels who had undergone computed tomography angiography (CTA) were referred to elective percutaneous coronary intervention. The morphology of coronary calcium was determined by CTA analysis. PMI was defined as an elevation in 24-h post-procedural cardiac troponin I levels of > 5 times the upper limit of normal with either symptoms of myocardial ischemia, new ischemic electrocardiographic changes, or documented complications during the procedure. Logistic regression was performed to identify the effect of the morphology of coronary calcium on the occurrence of PMI.

RESULTS

According to the presence or morphology of coronary calcium as shown by CTA, 210 subjects were grouped in the heavy calcification group, 258 in the mild calcification group, 40 in the spotty calcification group and 108 in the control group. The dissection rate was significantly higher in the heavy calcification group than in the control group (7.1 % vs. 1.9%, p = 0.03). The occurrence of PMI in the heavy calcification group was significantly higher than that in the control group (OR 4.38, 95% CI 1.80-10.65, p = 0.001). After multivariate adjustment, the risk of PMI still remained significantly higher in the heavy calcification group than in the control group (OR 4.04, 95% CI 1.50-10.89, p = 0.003).

CONCLUSIONS

The morphology of coronary calcium determined by CTA may help to predict the subsequent occurrence of PMI. A large amount of coronary calcium may be predictive of PMI.

Percutaneous coronary intervention in nonagenarians: pros and cons

Percutaneous coronary intervention is a mainstay in the management of symptomatic or high-risk coronary artery disease. The bulk of clinical evidence and experience underlying this fact relies, however, on relatively young patients. Indeed, few data of very limited quality are available which adequately define the risk-benefit and cost-benefit profile of coronary angioplasty and stenting in very old subjects, such as those of 90 years of age or older (i.e., nonagenarians). The aim of this review is to provide a concise, yet practical, synthesis of the available evidence on percutaneous coronary revascularization in the very elderly. The main arguments elaborated upon are to what extent we can extrapolate findings from studies including younger patients to nonagenarians, whether we should provide higher priority to prognosis or quality of life in such patients, and whether we can afford to allocate vast resources to care for such subjects in an era of financial constraints. Our review of 18 studies and 1082 patients suggest that percutaneous coronary intervention is feasible and associated with acceptable short- and long-term results in this population, which is nonetheless fraught with a high mortality risk irrespective of the revascularization procedure. Accordingly, the pros and cons of percutaneous coronary intervention should be carefully weighed when considering this treatment in nonagenarians.

The impact of plaque characterization assessed by intravascular ultrasound on myocardial perfusion after primary angioplasty in patients With ST-segment elevation myocardial infarction

BACKGROUND

Previous studies described that inadequate tissue perfusion after primary angioplasty in ST-elevation myocardial infarction (STEMI) patients is associated with adverse cardiac events. This study evaluated whether plaque morphological intravascular ultrasound (IVUS) characteristics affects tissue perfusion after stent implantation in STEMI patients.

METHODS AND RESULTS

A total of consecutive 306 STEMI patients who underwent primary angioplasty with IVUS were analyzed. Maximum ST-segment elevation before angioplasty was compared with ST-segment levels 60min after angioplasty. Percent ST-segment resolution (STR) was calculated and categorized as complete (>70%), partial (30-70%), and absent (<30%). Qualitative and quantitative IVUS analyses were performed using standard methods. Plaque with ultrasound attenuation was defined as IVUS finding with backward signal attenuation behind plaque >180° without dense calcium. One-hundred-fifty patients had complete, 101 had partial, and 55 had absent STR. The incidence of in-hospital death tended to be higher in absent STR than in partial and complete STR groups. Multivariate analysis indicated that remodeling index (P=0.004), the presence of ultrasound attenuation (P=0.02), percentage stent expansion (P=0.03), and the presence of deep calcium (P=0.049) were the independent predictors related to the occurrence of absent STR after angioplasty.

CONCLUSIONS

Positive vessel remodeling, plaque with ultrasound attenuation >180°, deep calcium, and stent overexpansion as assessed by IVUS are associated with the absence of STR after primary angioplasty in patients with STEMI.

Differential effects of post-dilation after stent deployment in patients presenting with and without acute myocardial infarction

BACKGROUND

In the practice of percutaneous coronary intervention, post-dilation often is performed after stent deployment to improve stent expansion. However, aggressive mechanical expansion is a risk factor of distal embolization and microvascular injury, especially for patients with acute myocardial infarction (AMI). Few studies have investigated the effects of post-dilation on medium-term clinical outcomes.

METHODS AND RESULTS

Patients enrolled in the multicenter NHLBI Dynamic Registry between 2001 and 2006 were evaluated. Patients who were treated with ≥ 1 stent were studied. Patients with cardiogenic shock or history of coronary artery bypass graft surgery were excluded. Patients were followed up to 1 year. Because of the significant statistical interaction (P = .02) between post-dilation and AMI status on the hazard of death/myocardial infarction (MI), post-dilation effects were estimated separately for patients who did and did not present with an AMI. Among the 1,358 patients who presented with an AMI, post-dilation was associated with a significantly higher risk of death/MI (hazard ratio [HR] = 1.78, 95% CI 1.12-2.83, P = .01), not associated with the risk of repeat revascularization (HR = 1.15, 95% CI 0.81-1.62, P = .43). Among the 3,001 patients who did not present with AMI, post-dilation was not associated with risks of death/MI (HR = 1.08, 95% CI 0.77-1.50, P = .67) or repeat revascularization (HR = 1.17, 95% CI 0.93-1.47, P = .19). Similar effects were observed for the restricted analysis with additional adjustment for lesion characteristics among the 1,039 AMI patients and 2,179 non-AMI patients with a single lesion treated.

CONCLUSIONS

Stent post-dilation is associated with an increased risk of death/MI in AMI patients but not in non-AMI patients. Further investigation is warranted.

Stent choice in primary percutaneous coronary intervention: drug-eluting stents or bare metal stents?

The controversial choice between bare metal stents and drug-eluting stents (DES) in primary percutaneous coronary intervention (PCI) seems to be driven by a growing body of evidence. Although evidence supporting the use of DES in the setting of ST-segment elevation myocardial infarction (STEMI) has been demonstrated, including a lower target vessel revascularization (TVR) rate without increased mortality, at present the proportion of DES implants in STEMI patients is low. This may be due to higher costs of DES, cultural issues, lack of concerns about restenosis in STEMI, lack of information on patient bleeding risk and the need for surgery within a limited time. In addition, initial enthusiasm about the efficacy of DES in reducing restenosis is now decreasing as a result of the safety concerns regarding in-stent thrombosis. Moreover, DES requires long-term dual antiplatelet therapy (DAT), which may pose problems in patients prone to bleeding or in candidates for elective surgery. Nevertheless, benefits associated with use of DES include significantly lower TVR rates without remarkable adverse effects in terms of death and myocardial infarction. Data about the efficacy of DES are still limited to 1-year follow-up in most trials. Uncoated stents permit early arterial wall healing, requiring a shorter duration of DAT and are potentially associated with a reduced risk of thrombus formation at long-term follow-up. Importantly, however, this potential late threat has not been confirmed in recent data from the limited number of studies with longer than 2-years follow-up. Anatomical features and individual risk profiles can sometimes help in the choice of the most suitable type of stent. In conclusion, stent choice in primary PCI cannot be standardized for all patients and appears to be influenced by various factors that need to be considered to provide better revascularization in terms of both efficacy and safety.

Baseline inflammation is not predictive of periprocedural troponin elevation after elective percutaneous coronary intervention

High-sensitivity C-reactive protein predicts future cardiovascular events in both healthy individuals and patients with unstable and stable coronary syndromes. Few data are available about the incidence and the relation to inflammation of troponin elevation following percutaneous coronary intervention (PCI), a potential predictor of longterm outcome. We sought to confirm the impact of embolization on long-term outcome and evaluate the ability of baseline inflammation to predict troponin elevation induced by PCI. We prospectively analyzed 200 patients treated by PCI for stable or Braunwald IIA class unstable angina. The patients were recruited between January 1997 and May 1999, and the population was followed during a mean follow-up of 32 months. Major adverse cardiac events (MACEs) were defined as the occurrence of death, myocardial infarction or recurrent angina requiring repeat PCI, or coronary artery bypass grafting. During the follow-up period, 58 MACEs were observed. By multivariate analysis, independent predictors for the occurrence of MACEs were unstable angina and troponin I level after PCI (P < 0.0001 for both). No correlation was found between baseline inflammation and significant troponin I elevation post PCI and by multivariate analysis, no biological variable was a predictor of troponin I elevation post PCI. Baseline inflammation cannot predict onset of minor myonecrosis damage (expressed by troponin elevation) induced by PCI, a significant predictor of long-term outcome in this setting.

A novel method of coronary stent sizing using intravascular ultrasound: Safety and clinical outcomes

OBJECTIVES

The use of intravascular ultrasound (IVUS) in guiding coronary stenting has increased in recent years. The feasibility, safety and clinical outcomes of a novel method of sizing coronary stents using IVUS have not been established. The main end points of the current study are the incidence of acute and short-term complications, and the need for target vessel revascularization at six months.

METHODS

Eighty-six patients underwent coronary stenting using IVUS imaging during the procedure. The optimal size of the stents was determined by using a novel method (the 'aggressive IVUS method'), ie, measuring the media-to-media dimensions of the coronary vessels at the site of the lesions using IVUS. A six-month follow-up chart review was performed following the initial stenting.

RESULTS

At six months, there were two noncardiac deaths in the group. There were no acute, subacute or late stent thromboses. Target vessel revascularization and major adverse cardiac event rates remained low - at 5.8% and 9.3%, respectively. The mean (± SD) IVUS-derived coronary stent size (3.89±0.98 mm) using the aggressive IVUS method was significantly different from the mean IVUS-derived coronary stent size (3.46±0.96 mm) using the 'traditional IVUS method'.

CONCLUSION

Aggressive sizing of the coronary stents by IVUS guidance is feasible and safe, and is associated with a favourable clinical outcome.

Predictors of periprocedural creatine kinase-myocardial band elevation complicating elective percutaneous coronary intervention

Limited data are available regarding the predictors of periprocedural creatine kinase-MB (CK-MB) isoenzyme increase after elective percutaneous coronary intervention (PCI) in the stenting era. We explored the predictors of periprocedural CK-MB increase in 882 consecutive patients with normal preprocedural CK-MB who underwent 919 angiographically successful elective PCIs with (n = 814) or without (n = 105) stenting. Patients were categorized into 3 groups based on their peak CK-MB levels after PCI: (1) normal CK-MB (n = 761), (2) minor CK-MB increase (CK-MB 1 to 3 times normal, n = 112), and (3) major CK-MB increase (CK-MB >3 times normal, n = 46). By logistic regression analysis, independent predictors for minor CK-MB increase included thrombus (odds ratio [OR] 5.09, p = 0.001), platelet IIb/IIIa antagonist use (OR 0.53, p <0.01), number of lesions treated (per additional lesion, OR 1.54, p <0.01), maximum balloon size (per millimeter increase, OR 1.57, p <0.05), American College of Cardiology/American Heart Association type C lesion (OR 1.68, p <0.05), sustained chest pain during procedure (OR 1.94, p <0.05), dissection (OR 2.05, p <0.05), and transient side branch occlusion (OR 4.54, p <0.05). Independent predictors for major CK-MB increase were chest pain at end of procedure (OR 9.66, p <0.001), type C lesion (OR 2.42, p <0.05), Canadian Cardiovascular Society angina class III to IV (OR 3.32, p <0.05), thrombus (OR 5.09, p = 0.001), and abrupt closure (OR 5.30, p <0.05). In conclusion, baseline clinical and angiographic characteristics and procedural complications were associated with minor and major CK-MB increases. Patients with chest pain at the end of the procedure were at the highest risk for major CK-MB increase.

Intracoronary ST-Segment Shift Soon After Elective Percutaneous Coronary Intervention Accurately Predicts Periprocedural Myocardial Injury

Background— Elevation of cardiac biomarkers after coronary angioplasty (percutaneous coronary intervention [PCI]) reflects periprocedural myocardial damage and is associated with adverse cardiac events. We assessed whether periprocedural myocardial damage that occurs despite successful PCI could be rapidly and easily identified by intracoronary ST-segment recording with the use of a catheter guidewire.

Methods and Results— In 108 consecutive stable patients undergoing elective single-vessel PCI, we recorded unipolar ECG from the intracoronary guidewire in the distal coronary before PCI and 2 minutes after the last balloon inflation. After PCI, intracoronary ST-segment shift ≥1 mm from baseline was considered significant. Troponin I levels were measured at baseline and at 8 and 24 hours after intervention, and myocardial damage was defined as troponin I increase above the upper normal value after intervention. All patients had normal cardiac marker values before PCI, and PCI was successful in all (residual stenosis <20%, Thrombolysis in Myocardial Infarction grade 3 flow). After PCI, long-term follow-up data were collected; myocardial damage was detected in 50 patients (46%), although abnormal creatine kinase-MB values were documented in only 11 (10%). Significant intracoronary ST-segment shift after PCI was present in 40 patients (37%; group A) and absent in the remaining 68 (63%; group B). Procedural myocardial damage was documented in 37 group A patients (93%) and in 13 group B patients (19%; P <0.001); significant ECG changes were found on standard ECG after intervention in only 5 patients (13%) and 1 patient (1%) ( P <0.05). Sensitivity of intracoronary ST-segment shift for predicting myocardial damage was 74%, and specificity was 95%, with positive and negative predictive values of 93% and 81%, respectively. On multivariate analysis, intracoronary ST-segment shift was the sole independent predictor of myocardial damage (odds ratio, 54.1; 95% confidence interval, 12.1 to 240; P <0.0001). At a median follow-up of 12±5 months, major coronary event–free survival was significantly worse in group A patients (log-rank test χ 2 =4.0; P <0.05).

Conclusions— After successful single-vessel PCI, intracoronary ST-segment shift allows the prompt and inexpensive identification of patients developing myocardial injury, who may require adjunctive therapy and longer in-hospital stay.

Randomized study on simple versus complex stenting of coronary artery bifurcation lesions: the Nordic bifurcation study

BACKGROUND

The optimal stenting strategy in coronary artery bifurcation lesions is unknown. In the present study, a strategy of stenting both the main vessel and the side branch (MV+SB) was compared with a strategy of stenting the main vessel only, with optional stenting of the side branch (MV), with sirolimus-eluting stents.

METHODS AND RESULTS

A total of 413 patients with a bifurcation lesion were randomized. The primary end point was a major adverse cardiac event: cardiac death, myocardial infarction, target-vessel revascularization, or stent thrombosis after 6 months. At 6 months, there were no significant differences in rates of major adverse cardiac events between the groups (MV+SB 3.4%, MV 2.9%; P=NS). In the MV+SB group, there were significantly longer procedure and fluoroscopy times, higher contrast volumes, and higher rates of procedure-related increases in biomarkers of myocardial injury. A total of 307 patients had a quantitative coronary assessment at the index procedure and after 8 months. The combined angiographic end point of diameter stenosis >50% of main vessel and occlusion of the side branch after 8 months was found in 5.3% in the MV group and 5.1% in the MV+SB group (P=NS).

CONCLUSIONS

Independent of stenting strategy, excellent clinical and angiographic results were obtained with percutaneous treatment of de novo coronary artery bifurcation lesions with sirolimus-eluting stents. The simple stenting strategy used in the MV group was associated with reduced procedure and fluoroscopy times and lower rates of procedure-related biomarker elevation. Therefore, this strategy can be recommended as the routine bifurcation stenting technique.

Adjunctive Balloon Postdilatation after Stent Deployment: Is It Still Necessary with Drug-Eluting Stents?

Deployment of bare metal stents (BMS) with current stent delivery systems is often associated with suboptimal stent expansion. Adjunctive postdilatation with noncompliant balloons has improved stent expansion with BMS and has been associated with less need for target vessel revascularization (TVR). Drug-eluting stents (DES) have proven highly effective in reducing restenosis and TVR and are now being used in the great majority of percutaneous coronary interventions. Because of the very low rates of TVR with DES, many operators have felt that postdilatation may no longer be necessary. In this review, we present data showing that stent expansion of DES (like BMS) using current stent delivery systems is frequently suboptimal. Furthermore, smaller mimimal stent area (MSA) and stent underexpansion following deployment of DES are strong predictors of stent thrombosis and TVR. Adjunctive postdilatation with noncompliant balloons can increase MSA and decrease the frequency of suboptimal stent deployment and potentially can reduce the frequency of stent thrombosis and TVR. Despite the lack of evidence from randomized clinical trials, we believe the observational data support the use of adjunctive balloon postdilatation following deployment of DES in the great majority of patients.

The new definition of myocardial infarction and the impact of troponin determination on clinical practice

OBJECTIVE

To discuss the more controversial clinical and laboratory aspects in the application of the new biochemical diagnostic standard for myocardial infarction, 4 years after its introduction, and to make some suggestions, which could allow for a more realistic application of the new definition in the current clinical practice.

METHODS

Studies published in the last 4 years in the most important cardiology and laboratory medicine journals (including proceedings of the international meetings), discussing advantages and limits of the new definition of myocardial infarction, were reviewed and pertinent data were discussed and compared with similar information available in literature.

RESULTS AND CONCLUSIONS

Although the exact status of implementation of the new definition of myocardial infarction cannot yet be known, the trend toward such recommendation is evolving significantly, even if at different rates in different countries. To make the transition smoother, major educational efforts are required to disseminate the conceptual reasoning behind the new guidelines. On the other hand, more knowledge is needed for some relevant issues, such as the different analytical performance of cardiac troponin assays or the prognostic significance of biomarker changes after a percutaneous coronary intervention.

Peri-procedural myocardial injury: 2005 update

During the past three decades, percutaneous coronary intervention has become one of the cardinal treatment strategies for stenotic coronary artery disease. Technical advances, including the introduction of new devices such as stents, have expanded the interventional capabilities of balloon angioplasty. At the same time, there has been a decline in the rate of major adverse cardiac events, including Q-wave acute myocardial infarction, emergency coronary artery bypass grafting, and cardiac death. Despite these advances, the incidence of post-procedural cardiac marker elevation has not substantially decreased since the first serial assessment 20 years ago. As of now, these post-procedural cardiac marker elevations are considered to represent peri-procedural myocardial injury (PMI) with worse long-term outcome potential. Recent progress has been made for the identification of two main PMI patterns, one near the intervention site (proximal type, PMI type I) and one in the distal perfusion territory of the treated coronary artery (distal type, PMI type II) as well as for preventive strategies. Integrating these new developments into the wealth of clinical information on this topic, this review aims at giving a current perspective on the entity of PMI.

Impact of platelet glycoprotein IIb/IIIa Inhibition on the paclitaxel-eluting stent in patients with stable or unstable angina pectoris or provocable myocardial ischemia (a TAXUS IV substudy)

Whether the benefits that glycoprotein IIb/IIIa inhibitors confer in patients who undergo bare metal stent implantation extend to drug-eluting stents is unknown. We performed a prespecified subgroup analysis of the TAXUS IV study population to examine the effect of procedural glycoprotein IIb/IIIa inhibition during paclitaxel-eluting stent implantation on periprocedural creatine kinase-MB (CK-MB) levels. Glycoprotein (GP) IIb/IIIa inhibitors were administered to 57.7% of patients who had been randomized to receive the TAXUS stent and to 56.7% of those who had been randomized to receive the control stent. Among patients who received the TAXUS stent, the rate of CK-MB increases of >3 times the normal level was 2.6-fold higher in those who received a GP IIb/IIIa inhibitor than in those who did not (11.4% vs 4.4%, p = 0.0015). Composite rates of major adverse cardiac events and target vessel failure were also higher at 1 month in the GP IIb/IIIa group. By multivariate analysis, use of GP IIb/IIIa inhibitors during stenting with the TAXUS stent was an independent predictor of CK-MB increases >3 times the normal level. Further studies are warranted.

Occurrence of Non-Q wave Myocardial Infarction Following Percutaneous Coronary Intervention in the Stent Era: Systematic Monitoring of the Three Markers of Myocardial Necrosis

OBJECTIVES

To compare the elevation of the three markers total creatine kinase (CK), CK-MB mass, and troponin I (TnI) and their relationship with clinical and procedural characteristics following percutaneous coronary intervention (PCI).

METHODS

We prospectively evaluated 385 patients consecutively undergoing successful PCI. The three markers were systematically measured before and at 6, 12, and 24 hours after PCI. Any increase above the upper normal limit (UNL) of any marker has been considered abnormal when basal values were normal, while a further increase was needed when basal values were altered. Patients with ongoing acute myocardial infarction were excluded from the analysis.

RESULTS

TnI was above UNL in 183 patients (51%); in 138 (38.5%) it was the only marker altered. CK-MB mass was elevated in 12.8% patients, more than 3x UNL in 5.5% and more than 5x UNL in 2.8%. In over one half of these patients, CK-MB values peaked at 12 hours following PCI. Total CK was above UNL in 23 patients only (6.4%) and more than twice UNL in 5 (1.4%). Only 1 patient out of the 5 with CK-MB mass more than 10x UNL had total CK higher than twice UNL. In our population, post-PCI elevation of myocardial necrosis markers correlate with the occurrence of minor procedural complications (observed overall in 7.8% cases; TnI and/or CK-MB > 1xUNL 96% vs 47.5%, P < 0.001) and the presence of higher complexity clinical and/or procedural features, such as multivessel disease, multivessel or multilesion PCI, multiple stenting and use of glycoprotein IIb/IIIa inhibitors.

CONCLUSIONS

The elevation of at least one biochemical marker of myocardial necrosis is frequent following successful PCI with routine stent implantation. CK-MB mass is the most practical marker, having optimal kinetic and peaking with the first 12-18 hours post-PCI. Definitive data on the prognostic role and the applicability for the diagnosis of myocardial infarction of minor elevation of CK-MB mass or isolated increase of TnI are lacking.

Is overdilatation of 3.0 mm sirolimus-eluting stent associated with a higher restenosis rate?

We evaluated the safety and effectiveness of postdilating a 3.0 mm sirolimus-eluting stents (SESs; six cells) with a 3.5-4.0 mm balloon. We identified 254 consecutive patients who underwent percutaneous coronary interventions using SESs with a nominal diameter of 3.0 mm (six cells). Patients were divided into two groups based on whether they were subsequently postdilated with a 3.0 mm (group 1: 168 patients, 251 lesions) or a 3.5-4 mm balloon (group 2: 86 patients, 102 lesions). There were no significant differences regarding the incidence of in-hospital and long-term follow-up. Angiographic follow-up was available in 72% and 74% of groups 1 and 2, respectively. The two groups had no significant differences regarding late lumen loss (0.51 +/- 0.36 vs. 0.52 +/- 0.33; P = 0.3) and binary restenosis rates (10.7% vs. 8.8%; P = 0.1). Six-month clinical follow-up was available in all patients. At long-term follow-up (mean: 10.6 +/- 3.7 for group 1 and 11.3 +/- 3.9 months for group 2), there were no significant differences between the two groups regarding major adverse cardiac events (8.9% vs. 9.2%; P = 0.9). Implantation of a 3.0 mm SES with postdilation with a 3.5-4 mm balloon did not result in any significant difference in complications, in-hospital non-Q-wave myocardial infarction, binary restenosis, or target lesion revascularization. These data should lessen concern that overdilation may dilute the beneficial effects of SESs.

Creatine kinase-MB enzyme elevation and long-term clinical events after successful coronary stenting in lesions with ruptured plaque

Patients with acute coronary syndrome are at increased risk of acute and long-term events after stent implantation. We compared the impact of intravascular ultrasound detected plaque rupture on creatine kinase-MB (CK-MB) isoenzyme release and clinical outcomes by comparing 62 patients with ruptured plaques with 62 matched control patients who underwent stent implantation. Two thirds of the patients in each group presented with an acute coronary syndrome. There were no differences in procedural complications between groups, although patients with ruptured plaque had higher CK-MB elevation rates than those without ruptured plaque (1 to 3 times the upper limit of normal CK-MB, 35% vs 10%, p <0.001; >3 times the upper limit, 15% vs 2%, p = 0.02). Independent predictors of CK-MB elevation were presence of ruptured plaque (p = 0.03) and unstable angina (p = 0.04). Patients with ruptured plaque had higher composite rates of late events (target lesion revascularizations/myocardial infarctions/cardiac deaths) than controls (25% vs 9%, p = 0.03). These results were similar when only patients with acute coronary syndrome were studied. Plaque rupture morphology is associated with higher periprocedural CK-MB release and worse 1-year clinical outcome in patients treated with coronary stenting.