Effectiveness of coronary stent deployment without predilation

Cardiac Troponin I Increase After Successful Percutaneous Coronary Angioplasty: Predictors and Long-Term Prognostic Value

After successful percutaneous coronary interventions (PCI), elevations of cardiac enzymes are not rare, but it is still not clear whether those elevations are associated with adverse late outcome. The purpose of the study was to investigate the relation between cardiac troponin I (cTn-I) increase after successful percutaneous intervention and late outcome. The study consisted of 100 consecutive patients (mean age 56 ±9.8, 84% male) who had successful elective coronary balloon angioplasty with or without stent implantation. Patients with stable angina (n=54) and unstable angina (n=46) were included in the study. Blood samples for measurement of cTn-I were taken before and immediately after the procedure, and every 6 hours for the first 24 hours. Patients with preprocedural cTn-I elevation were excluded from the study. Postprocedural cTn-I elevation was detected in 34 patients (34%, troponin (+) group) and cTn-I levels were normal in 66 patients (66%, troponin (-) group). Logistic regression analysis showed that intervention in patients with unstable angina, stent implantation following balloon dilation, and maximal inflation pressure were the predictors of cTn-I elevation (p=0.035, p=0.038, and p=0.014, respectively). During the prospective follow-up period for 21 ±7.5 months, the incidence of major cardiac events including recurrent angina, acute myocardial infarction, death, and revascularization were not different in patients with and without cTn-I elevation. Overall, major cardiac events occurred in 9 patients (26%) in the troponin (+) group and in 13 patients (20%) in the troponin (-) group. Kaplan-Meier survival analysis showed that cTn-I elevation was not an important correlate of overall cardiac events (log-rank: 1.66, p=0.19). The authors conclude that postprocedural cTn-I elevation is related to unstable angina, stent implantation following predilation, and inflation pressure, and there is no association with minor myocardial injury occurring after successful percutaneous coronary intervention and late adverse cardiac events.

Effects of Direct Stent Implantation and Conventional Stent Implantation on Minor Myocardial Injury

Direct coronary stenting without balloon predilation has the potential benefits of a reduced risk of extended dissections, reduced fluoroscopy exposure, reduced procedural time, and potential cost savings. The purpose of the study was to compare the effects of angiographically successful direct stent implantation and conventional stent implantation (stent implantation following predilation) on minor myocardial injury characterized by cardiac troponin I (cTn-I), and cardiac troponin T (cTn-T) elevation. The authors prospectively studied 42 patients who had successful direct stent implantation, and 49 patients who had successful conventional stent implantation. Blood samples for measurement of cTn-I and cTn-T were taken before, and immediately after the procedure, and every 6 hours for the first 24 hours. cTn-T elevation was observed in 6 patients (14.3%) in the direct stent implantation group, and in 16 patients (32.6%) in the conventional stent implantation group (p: 0.03). Similarly cTn-I elevation was more frequent in the conventional stent implantation group (20 patients, 40.8%) than direct stent implantation group (7 patients, 16.7%, p: 0.02). Stent implantation following predilation is more frequently associated with postprocedural minor myocardial injury than direct stent implantation.

Direct stenting with sirolimus-eluting stents

The sirolimus-eluting stent has been studied extensively in randomized controlled trials of patients with native de novo coronary lesions. Lesion predilation before stent placement has been the predominant implantation strategy in these trials. Direct implantation of the sirolimus-eluting stent without lesion predilation has been undertaken at the investigators' discretion in certain trials as well as in patients enrolled in a post-marketing surveillance registry, and was the intended implantation strategy in the DIRECT trial. Comparisons with patients receiving sirolimus-eluting stents after lesion predilation in the trials and the registry were all confounded by imbalances in patient, lesion, and/or procedural characteristics and point to the highly selective nature of the direct-stenting strategy. At present, direct implantation of the sirolimus-eluting stent appears to be safe and as effective as conventional (predilated) stenting, provided that the targeted coronary lesion is amenable to the direct approach. Since a randomized trial of implantation strategies is lacking, there is no conclusive evidence as to the hypothesized superiority of direct over predilated stenting in suitable coronary lesions.

Comparison of the X-SIZER Thrombectomy Device with Adjunct Abciximab During Primary Angioplasty and Stenting for ST-Segment Elevation Myocardial Infarction

OBJECTIVE

To evaluate the safety and efficacy of the X-SIZER thrombectomy device versus the use of abciximab during primary angioplasty for acute ST-elevation myocardial infarction (STEMI).

DESIGN

Retrospective analysis of patients undergoing primary angioplasty for STEMI from October 2000 to December 2002 using the X-SIZER thrombectomy device versus abciximab.

SETTING

National University Hospital, Singapore.

PATIENTS

Out of 79 patients, 44 underwent X-SIZER use, while 35 received adjunct abciximab. Both groups were similarly represented with regards to age, gender, risk factors, target vessel site/diameter, cardiogenic shock, and onset of chest pain to procedure time. The infarct-related artery was occluded in 88.6% in both groups.

INTERVENTIONS

A 2-mm X-SIZER was used in 34/44 (77.3%), while a 1.5-mm device was used in the remainder. Final TIMI 3 flow was obtained in 38/44 (86.4%) in the X-SIZER group compared to 26/35 (74.3%) in the abciximab group (P = 0.175).

MAIN OUTCOME MEASURES

Coronary TIMI flow rate, electrocardiogram (ECG) resolution, slow flow/no reflow phenomenon, and patient outcome (death, cardiac failure, or repeat revascularization) at 1 month.

RESULTS

ECG resolution and slow flow/no reflow were better in the X-SIZER group (77.3% vs 54.3%, P = 0.031; 9.1% vs 25.7%, P = 0.047, respectively). Patient outcome at 1 month was, however, not significantly different (18.2% vs 17.1%, P = 0.904, respectively, for X-SIZER and abciximab).

CONCLUSION

X-SIZER thrombectomy during primary percutaneous coronary intervention for thrombus-laden STEMI is a safe and effective strategy. When compared to patients receiving abciximab, it was associated with improved ECG resolution, less slow flow/no reflow and a trend to better TIMI 3 flow.

Long-Term Follow-Up After Angiographically Successful Coronary Stenting Direct Stent Versus Conventional Stent Implantation

The purpose of the study was to compare the impacts of angiographically successful direct stent implantation and conventional stent implantation (stent implantation following predilatation) on long-term major cardiac events. The authors prospectively studied 40 patients who had successful direct stent implantation and 46 patients who had successful conventional stent implantation. The end-point of the study was defined as the occurrence of a major cardiac event, including recurrent angina, acute myocardial infarction, death, and target vessel revascularization. The demographic and clinical characteristics of the study groups were similar, except the indication of percutaneous angioplasty, which was more frequently unstable angina in the conventional stent group (63% vs 38%, P: 0.03). Procedural minor complications were more frequent in conventional stent implantation, and there was also a positive correlation between the conventional stent implantation and procedural minor complications (r = 0.231, P: 0.03), and postprocedural troponin elevation (r = 0.221, P: 0.04). The incidences of major cardiac events including recurrent angina, acute myocardial infarction, death, death or myocardial infarction, and target vessel revascularization were not different between the study groups during the long-term follow-up period (21 +/- 7.1 months for direct stent group and 20 +/- 7.5 months for conventional stent group). Overall end-points occurred in 9 patients (22%) in the direct stent group and in 9 patients (19%) in the conventional stent group. Kaplan-Meier survival analysis showed that there was no difference in event-free survival between the patients treated with direct stent implantation and conventional stent implantation (log-rank: 1.52, P = 0.21). Two-vessel intervention and hypertension were found to be related with long-term major cardiac events (r = 0.214, P: 0.048, r = 0.206, P: 0.04, respectively). In addition to the procedural advantages, direct stent implantation may also provide comparable results with conventional stent implantation concerning the late cardiac events following successful percutaneous coronary angioplasty.

Direct Stent Implantation Using the EXPRESStm Coronary Stent System:. Results of a Multi-Center Feasibility Study

The aim of this prospective, multicenter, single arm study was to assess the safety and feasibility of EXPRESS Coronary Stent implantation in native coronary arteries without balloon predilatation. Forty-two patients with de novo or restenotic lesions were enrolled, of which 38 were eligible for analysis. The coronary lesions were predominantly complex, occurring in arteries with a mean reference diameter of 2.80 +/- 0.49 mm. Technical and procedural success were achieved in 89.5% and 84% of the cases respectively. The mean minimal lumen diameter increased from 1.08 +/- 0.26 mm to 2.55 +/- 0.44 mm and diameter stenosis decreased from 61 +/- 7% to 13 +/- 8%. The primary endpoint of major adverse cardiac events at 30 days was 2.6% and was limited to only one event (target vessel revascularization, nontarget lesion). No other MACE were observed during the three-month follow-up period. Based on the findings of this study, direct stenting with the EXPRESS Stent appears feasible and is well tolerated.

Effect of direct stenting on clinical outcome in patients treated with percutaneous coronary intervention on saphenous vein graft

BACKGROUND

Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with frequent postprocedural enzyme elevation and late cardiac events. New strategies are proposed to minimize distal embolization and to improve the outcome of patients treated with stenting for SVG lesions. The objectives of the current study were to examine direct stenting (DS) strategy of PCI in SVG lesions and its effects on creatine-kinase (CK) release, major adverse cardiac events (MACE), and late outcome when compared to conventional stenting (CS).

METHODS

A consecutive series of 527 patients treated with stent implantation for SVG stenosis was analyzed. In this cohort, 170 patients with 229 lesions were treated with DS and 357 patients with 443 lesions were treated with CS. The inhospital and 12-month follow-up events were recorded and reported.

RESULTS

Baseline clinical and postprocedural angiographic characteristics were similar between the 2 groups except for higher preprocedural prevalence of thrombus-containing lesions in the DS group. Patients in the DS group had less CK-MB release (P <.001), and less non-Q-wave myocardial infarction (P =.024). Multivariate analysis detected unstable angina (odds ratio [OR] = 1.8, P =.03) as a correlate for non-Q-wave MI; DS was inversely associated with non-Q-wave myocardial infarction (OR = 0.65, P =.04). At 1 year, the target lesion revascularization-MACE was significantly lower in the DS group (P =.021). Multivariate analysis showed that DS (OR = 0.47, P =.007) was associated with reduction of the target lesion revascularization-MACE.

CONCLUSIONS

When feasible, DS may be the best approach for treating SVG stenosis.

Direct coronary stenting without balloon predilation of lesions requiring long stents: immediate and 6-month results of a multicenter prospective registry

To assess the outcomes of direct coronary stenting (DS) using long stents and examine predictive factors of DS failure, this prospective multicenter registry included 128 consecutive patients who underwent the implantation of stents >or= 18 mm in length without balloon predilation for de novo coronary artery stenoses. Mean lesion and stent lengths were 20.7 +/- 5.4 and 21.4 +/- 3.8 mm, respectively. Rates of DS success, lesion success, and primary success were 82%, 99%, and 97.7%, respectively. At 6 months, rates of MACE and TVR were 12.5% and 6.3%, respectively. In multivariate analysis, factors predictive of DS failure vs. DS success were presence of calcifications (78% vs. 45%; P = 0.004) and reference vessel diameter (2.77 +/- 0.4 vs. 3.13 +/- 0.42 mm; P = 0.0002). DS of complex lesions with stents >or= 18 mm in length was performed safely and with a high success rate. This strategy was less successful in the treatment of small vessels and in presence of calcifications.

A randomized comparison of direct stenting with conventional stent implantation in selected patients with acute myocardial infarction

OBJECTIVES

We sought to determine whether direct stenting might prevent the adverse events associated with stent implantation during primary angioplasty and to compare it with conventional stent implantation in patients with acute myocardial infarction (AMI).

BACKGROUND

No trial has demonstrated that stents favorably influence mortality rate. Recent studies have even suggested a negative impact of stents on coronary blood flow and clinical outcome.

METHODS

Of 409 patients treated by primary angioplasty with stent implantation in our center, 206 (50%) were enrolled in this randomized, single-center trial and allocated to direct stent implantation (n = 102) or stent implantation after balloon pre-dilation (n = 104). The study end points included angiographic results (final corrected Thrombolysis In Myocardial Infarction [TIMI] frame count and a composite end point of slow and no-reflow or distal embolization), an electrocardiogram marker of myocardial reperfusion assessment (ST-segment resolution) and in-hospital clinical outcome (death and recurrent infarction).

RESULTS

Direct stent implantation failed in eight patients but succeeded after pre-dilation in all. A non-significant increase in TIMI flow grade 3 was achieved after direct stenting (95.1% vs. 93.3%, p = 0.74) without significant difference in the corrected TIMI frame count (31.5 +/- 17 and 35.2 +/- 20 frames after direct and conventional stent, respectively, p = 0.42). The composite angiographic end point was significantly reduced by direct stent implantation (11.7% vs. 26.9%, p = 0.01). ST-segment resolution was also significantly improved after direct stent (no ST-segment resolution in 20.2% vs. 38.1% after direct and conventional stent, respectively, p = 0.01). Death and/or recurrent infarction occurred in six patients after conventional stent implantation and in two patients after direct stenting (p = 0.28).

CONCLUSIONS

In selected patients with AMI, direct stenting can be applied safely and effectively. This strategy may result in a significant reduction of microvascular injury, as suggested by improved ST-segment resolution after reperfusion with major potential clinical consequences.

A randomized trial of stenting with or without balloon predilation for the treatment of coronary artery disease

BACKGROUND

Stent placement has historically been preceded by predilation of the target lesion with percutaneous transluminal coronary angioplasty. Direct stent implantation, without predilation, has the potential to have a favorable impact on procedure cost by reducing the number of devices used, contrast administered, and procedure time.

METHODS AND RESULTS

We conducted a prospective randomized trial to compare the economic outcome of stenting with or without predilation. Inclusion criteria included intention to treat a single lesion with a coronary stent in a vessel with a reference diameter >2.4 mm. Exclusion criteria included total occlusions, culprit lesion within a saphenous vein graft, lesion length >25 mm, patients within 48 hours of an acute myocardial infarction, and patients unable to be treated with aspirin and clopidogrel. From September 1999 to March 2000, 77 patients were randomized to direct stent implantation (n = 37) or balloon-facilitated stenting (n = 40). Stent placement was successful in all patients. Crossover to predilation was required in 2 patients in the direct stent group because of inability to deliver the stent. Compared with balloon-facilitated stenting, direct stenting used fewer catheter devices (1.4 +/- 0.7 vs 2.5 +/- 0.8, P <.001), less contrast (92.7 +/- 43.1 mL vs 117.4 +/- 61.0 mL, P =.04), and less fluoroscopy time (7.5 +/- 3.9 minutes vs 11.6 +/- 8.3 minutes, P =.006). No difference in procedural complications or predischarge outcome was found. No difference in major adverse cardiovascular events was found at 6-month follow-up.

CONCLUSION

Direct stenting is a safe and successful procedure that reduces the number of devices used, fluoroscopy time, and contrast administration.

Randomised comparison of coronary stenting with and without balloon predilatation in selected patients

BACKGROUND

The SWIBAP (stent without balloon predilatation) prospective randomised trial was designed to compare direct coronary stenting with stenting preceded by lesion predilatation with an angioplasty balloon.

OBJECTIVE

To determine the feasibility and safety of direct stenting in non-complex coronary lesions in a prospective study.

PATIENTS AND DESIGN

All patients < 76 years of age scheduled to undergo angioplasty of a non-complex, non-calcified lesion in a coronary artery of > 3.0 mm, who granted their informed consent, were randomised into the trial. In group I, the stent was placed without balloon predilatation, while in group II stent implantation was preceded by balloon predilatation. The primary end point was the angiographic result according to procedure assigned by randomisation. An intravascular ultrasound substudy was performed in 60 patients.

RESULTS

Stent implantation was successful without predilatation in 192 of the 197 group I patients (97.5%), and with predilatation in 197 of the 199 group II patients (99%) (NS). No in-hospital stent thrombosis or death occurred. Overall procedural times, fluoroscopy times, and volumes of contrast agent given (mean (SD)) in group I v group II were 23.50 (13.54) min v 27.96 (15.23) min (p = 0.002), 6.04 (4.13) min v 6.67 (3.65) min (NS), and 135 (65) ml v 157 (62) ml (p < 0.001), respectively. No major adverse cardiovascular events had occurred by 30 days.

CONCLUSIONS

The feasibility and safety of direct stenting of selected and non-complex coronary lesions is confirmed. This technique was as successful as the conventional approach and was associated with a minor reduction in fluoroscopic exposure and procedure time and the administration of less contrast agent.

Comparison of direct coronary stenting with and without balloon predilatation in patients with stable angina pectoris. BET (Benefit Evaluation of Direct Coronary Stenting) Study Group

The purpose of this study was to compare the effects of stent placement with and without balloon predilatation on duration of the procedure, reduction of procedure-related costs, and clinical outcomes. Although preliminary trials of direct coronary stenting have demonstrated promising results, the lack of randomized studies with long-term follow-up has limited the critical evaluation of the role of direct stenting in the treatment of obstructive coronary artery disease. Between January and September 1999, 338 patients were randomly assigned to either direct stent implantation (DS+; 173 patients) or standard stent implantation with balloon predilatation (DS-; 165 patients). Baseline clinical and angiographic characteristics were similar in the 2 groups. Procedural success was achieved in 98.3% of patients assigned to DS+ and 97.5% of patients assigned to DS- (p = NS), with a crossover rate of 13.9%. Compared with DS-, DS+ conferred a dramatic reduction in procedure-related cost ($956.4 +/- $352.2 vs $1,164.6 +/- $383.9, p <0.0001) and duration of the procedure (424.2 +/- 412.1 vs 634.5 +/- 390.1 seconds, p < 0.0001). At 6-month follow-up, the incidence of major adverse cardiac events including death, angina pectoris, myocardial infarction, congestive heart failure, repeat angioplasty, or coronary artery bypass graft surgery was 5.3% in DS+ and 11.4% in DS- (p = NS). Multivariate analysis demonstrated that major adverse cardiac events rates were related to stent length of 10 mm (relative risk [RR] 3.25, 95% confidence intervals [CI] 1.36 to 7.78; p = 0.008), stent diameter of 3 mm (RR 2.69, 95% CI 1.03 to 7.06; p = 0.043), and complex lesion type C (RR 2.83, 95% CI 1.02 to 7.85; p = 0.045). Thus, in selected patients, this prospective randomized study shows the feasibility of DS+ with reduction in procedural cost and length, and without an increase in in-hospital clinical events and major adverse cardiac events at 6-month follow-up.

Coronary stenting without predilatation (SWOP): applicable technique in everyday practice

To evaluate the feasibility of stenting without predilatation, we registered all interventional procedures over a 6-month period. Six hundred patients were registered, and 684 lesions were treated. Interventions were divided into four groups: stenting without predilatation (SWOP), 221 lesions (32.4%); primary stenting with predilatation (PDS), 161 lesions (23.5%); provisional stenting (PRS), 131 lesions (19.2%); and plain-old balloon angioplasty (POBA), 171 lesions (25%). Interventional strategy was at the discretion of the operator based on few simple angiographic criteria and his clinical judgment. Procedural success was similar in all stent groups. We conclude that when primary stenting is planned, about 60% of lesions can be treated by SWOP effectively with excellent procedural results and considerable cost saving.