Local lesion-related factors and restenosis after coronary angioplasty. Evidence from a quantitative angiographic study in patients with unstable angina undergoing double-vessel angioplasty

Failure of drug-coated balloon angioplasty to treat bare metal in-stent restenosis accompanied by late stent thrombosis but successful treatment of binary in-stent restenosis

Drug-coated balloons (DCB) are effective in treating in-stent restenosis (ISR) with neointimal proliferation after bare-metal stent (BMS) implantation, but it is unclear whether DCB are effective in treating BMS-ISR accompanied by thrombosis. An 84-year-old man with previous inferior myocardial infarction and atrial fibrillation developed acute myocardial infarction (AMI) during hospitalization for intracerebral hemorrhage. Emergent coronary angiography (CAG) revealed severe stenosis of the distal left circumflex coronary artery. We implanted a BMS to avoid long-term triple antithrombotic therapy. He received aspirin, clopidogrel, and rivaroxaban for 1 month and then received clopidogrel and rivaroxaban. Seventy days after BMS implantation, he developed AMI, and emergent CAG revealed occlusion of the BMS due to late stent thrombosis. After thrombus aspiration, intravascular ultrasound showed incomplete neointimal healing in the proximal portion of the stent and excessive neointimal proliferation in the distal portion of the stent. DCB angioplasty of the entire BMS was performed after scoring balloon pre-dilation. Seven months after BMS implantation, follow-up CAG revealed binary ISR. DCB angioplasty of the entire BMS was performed again after scoring balloon pre-dilation. Thirteen months after BMS implantation, follow-up CAG did not reveal recurrence of ISR. <Learning objective: Drug-coated balloons (DCB) were ineffective when there was excessive neointimal proliferation accompanied by thrombosis, but effective in binary in-stent restenosis (ISR). DCB may be ineffective in early ISR after bare-metal stent implantations and when there is excessive neointimal proliferation accompanied by thrombosis. Since the safety and efficacy of DCB to treat excessive neointimal proliferation occurring with late stent thrombosis is unclear, further studies are needed.>.

Right ventricular involvement in acute left ventricular myocardial infarction: prognostic implications of MRI findings

OBJECTIVE

The purpose of this study was to investigate the prevalence and prognostic importance of the cardiac MRI finding of right ventricular involvement in patients with acute ST-segment elevation myocardial infarction (MI).

SUBJECTS AND METHODS

Fifty patients (41 men, nine women; mean age, 58 +/- 11 years) with first-ST-segment elevation MI underwent 1.5-T cardiac MRI immediately after successful percutaneous coronary intervention. The cardiac MRI protocol included steady-state free precession cine sequences for functional assessment of the left, right, and both ventricles and inversion recovery FLASH delayed enhancement sequences after contrast administration for the quantification of myocardial damage. The prevalence of right ventricular involvement detected with ECG and echocardiography was compared with the prevalence detected with cardiac MRI, which was the reference standard. Patients underwent follow-up for 32 +/- 8 months.

RESULTS

Right ventricular involvement was diagnosed with cardiac MRI in 27 patients (54%): 14 of 30 patients (47%) with inferior ST-segment elevation MI and 13 of 20 patients (65%) with anterior ST-segment elevation MI. ECG and echocardiographic findings showed only moderate agreement with cardiac MRI findings in the detection of right ventricular involvement in inferior acute MI (kappa = 0.38). Patients with right ventricular involvement in anterior ST-segment elevation MI had larger infarcts (delayed enhancement, 25.9% +/- 14.5% vs 11.4% +/- 10.1%; p = 0.030), lower left ventricular ejection fraction (34.3% +/- 8.2% vs 45.2% +/- 9.5%; p < 0.015), and lower right ventricular ejection fraction (39.8% +/- 6.6% vs 54.9% +/- 8.8%; p < 0.001) than those without right ventricular involvement. In a multivariate logistic regression model, right ventricular involvement was a strong independent predictor (odds ratio, 15.8; 95% CI, 4-63%) of major cardiac adverse events.

CONCLUSION

Right ventricular involvement in ST-segment elevation MI is detected more frequently with cardiac MRI than with ECG and echocardiography and is an independent prognostic indicator.

Single-center randomized evaluation of paclitaxel-eluting versus conventional stent in acute myocardial infarction (SELECTION)

OBJECTIVES

To evaluate the superiority of the paclitaxel-eluting stent (PES) in reducing neointimal hyperplasia (NIH) over its corresponding bare metal stent (BMS) during primary percutaneous coronary intervention (PCI).

BACKGROUND

Primary PCI with stent implantation is the repercussion strategy of choice for ST-elevation myocardial infarction (STEMI); nonetheless restenosis rate is still high. Drug-eluting stents have been proven to reduce restenosis rate in many settings, but their use during primary PCI is still controversial.

METHODS

Consecutive patients with STEMI <12 hours were randomized to receive PES or BMS. The primary end-point was the percentage of the stent volume obstructed by neointimal proliferation (NIH) measured by intravascular ultrasound (IVUS) at a 7-month angiographic follow-up. Secondary end-points were binary restenosis rate and major adverse cardiac events (MACE, i.e., death, nonfatal myocardial infarction, and target lesion revascularization).

RESULTS

Eighty patients with STEMI were randomized into the PES or BMS group. Patients were well matched for baseline characteristics and the index procedure was always successful. In-hospital and 1-month MACE were 2.5% per group. NIH at 7 months was 4.6% versus 20% (P< 0.01), late lumen loss 0.1 versus 1.01 mm (P = 0.01). MACE were 7.5% versus 42.5% (P = 0.001) with no difference in death and recurrent myocardial infarction rates. Late-acquired incomplete stent apposition (ISA) rate was 5.1% versus 2.7% (P = 0.65). One subacute stent thrombosis was reported in each group.

CONCLUSIONS

PES was superior to its corresponding BMS in reducing NIH in the STEMI setting without any increase in early and long-term clinical adverse events.

Impact of Stable Versus Unstable Coronary Artery Disease on 1-Year Outcome in Elective Patients Undergoing Multivessel Revascularization With Sirolimus-Eluting Stents

OBJECTIVES

We sought to evaluate the impact of unstable coronary artery disease (CAD) on short- and mid-term outcomes in patients with multivessel disease treated by multiple sirolimus-eluting stents (SES) as part of ARTS II (Arterial Revascularization Therapies Study Part II).

BACKGROUND

The differential safety/efficacy profile of SES when implanted in patients with unstable angina (UA) in comparison with stable angina (SA) undergoing multivessel intervention is largely unknown.

METHODS

Between February 2003 and November 2003, 607 patients at 45 participating centers were treated; 221 of them (36%) presented with UA.

RESULTS

At 30 days, the cumulative rate of death, myocardial infarction-defined as any creatine kinase (CK)/CK-myocardial band elevation beyond the upper limit of normal-cerebrovascular accident, and repeat revascularization (i.e., major adverse cardiac and cerebrovascular events [MACCEs]) was 19.9% in both groups. Angiographic subacute stent occlusion was documented in 1 (0.5%) and 4 (1%) patients in the UA and SA groups, respectively. At 1 year, the cumulative incidence of MACCEs was 27.1% in the UA and 24.9% in the SA group (p = 0.56). Two late occlusions occurred, both in the SA group. After adjustment for baseline and procedural characteristics, the presence of UA was not identified as an independent predictor of MACCE (hazard ratio 0.94; 95% confidence interval 0.41 to 2.12; p = 0.88). These findings remained consistent after increasing the CK/CK-myocardial band threshold to define periprocedural myocardial infarction up to at least 3 or 5 times the upper limit of normal.

CONCLUSIONS

In ARTS II, an unstable clinical presentation did not exert a negative impact on short- and mid-term outcome after SES implantation for multivessel disease. (ARTS II Trial; ; NCT00235170).

Contrast-enhanced cardiovascular magnetic resonance imaging of right ventricular infarction

OBJECTIVES

We assessed the role of late enhancement cardiovascular magnetic resonance imaging (LE-CMR) for the diagnosis of right ventricular infarction (RVI).

BACKGROUND

Right ventricular infarction occurs in about one-half of patients with inferior myocardial infarction (MI). It is associated with an unfavorable prognosis, but established methods often lack the diagnostic accuracy to detect it. Late enhancement cardiovascular magnetic resonance imaging accurately detects left ventricular MI.

METHODS

Thirty-seven patients with acute inferior MI were included. To test for RVI, they prospectively underwent a physical examination, an electrocardiogram (ECG) for ST-segment elevation in the V4r right precordial lead, and an echocardiogram. After coronary reperfusion, LE-CMR was performed for assessing presence and extent of late enhancement in the right ventricular (RV) wall. The LE-CMR data were compared with the other results; interobserver variability was assessed. The LE-CMR was repeated after 13 months.

RESULTS

Late enhancement cardiovascular magnetic resonance imaging detected RVI in 21 of 37 (57%) patients with acute inferior MI. Interobserver variability was very good (kappa 0.83); physical exam was positive for RVI in 7 of 37 (19%) patients, V4r ECG in 13 of 37 (35%) patients, and echocardiogram in 6 of 37 (16%) patients. The LE-CMR findings for RVI showed only mild agreement with findings for RVI on physical exam (kappa 0.30), V(4)r ECG (kappa 0.38), and echocardiography (kappa 0.32). Irreversible injury of the RV persisted at 13 months (kappa 0.85).

CONCLUSIONS

In patients with acute inferior MI, RVI is more frequently detected by LE-CMR than by current standard diagnostic techniques. Further CMR studies might allow for analyzing its clinical and prognostic relevance.

Overcommitment predicts restenosis after coronary angioplasty in cardiac patients

The objective of this study is to examine the role of a particular stress-enhancing psychosocial risk factor, termed overcommitment, in predicting restenosis after successful percutaneous transluminal coronary angioplasty (PTCA). Overcommitment defines a personal pattern of coping with demands characterized by excessive striving in combination with a strong desire of being approved and esteemed. One hundred six consecutive male patients with coronary artery disease who underwent PTCA were followed over a mean of 12 months. The restenosis rate as defined by quantitative angiography was 34%. Multivariate analysis revealed independent effects of high density lipoprotein cholesterol (odds ratio [OR] 3.19), age (OR 3.43), and overcommitment (OR 2.86) on risk of restenosis. In conclusion, a stress-enhancing psychosocial person characteristic termed overcommitment acts as an independent predictor of coronary restenosis after PTCA. As overcommitment is subject to cognitive-behavioral intervention, results have implications for a more comprehensive approach to secondary prevention in cardiac patients.

Outcomes with the paclitaxel-eluting stent in patients with acute coronary syndromes

OBJECTIVES

We sought to investigate the outcomes of paclitaxel-eluting stent implantation in patients with unstable angina or non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention (PCI).

BACKGROUND

Whether the paclitaxel-eluting stent is safe and effective in patients with acute coronary syndromes (ACS) is unknown.

METHODS

In the TAXUS-IV trial, 1,314 patients with stable or unstable ischemic syndromes undergoing PCI were randomized to treatment with either the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). The results were stratified by the acuity of the presenting clinical syndrome.

RESULTS

Acute coronary syndromes were present in 450 patients (34.2%), 237 of whom were assigned to paclitaxel-eluting stents and 213 to bare-metal stents. The baseline and procedural characteristics were well matched between the groups. Clinical outcomes at 30 days were similar with both stents. At one-year follow-up, patients with ACS assigned to the paclitaxel-eluting stent compared to the control stent had strikingly lower rates of target lesion revascularization (TLR) (3.9% vs. 16.0%, p < 0.0001) and major adverse cardiac events (11.1 vs. 21.7%, p = 0.002). By multivariate analysis, ACS was an independent predictor of in-stent restenosis in the cohort treated with bare-metal stents (hazard ratio [HR] = 2.03 [95% confidence interval (CI) 1.05 to 3.92], p = 0.035), while among patients randomized to the paclitaxel-eluting stents, ACS was an independent predictor of freedom from restenosis (HR = 0.27 [95% CI 0.08 to 0.97], p = 0.04).

CONCLUSIONS

The use of the paclitaxel-eluting TAXUS stent was safe in patients with unstable ischemic syndromes, and was associated with marked reduction of ischemia-driven TLR and adverse cardiac events at one year.

Les facteurs prédictifs de la resténose : quels changements avec les stents « actifs » ?

For many years, restenosis was the major limiting factor of coronary angioplasty, even since the systematic use of stents. Numerous scientific publications have aimed to define the predictive factors of this phenomenon. Factors such as diabetes, the size of the treated artery, the use of stents or not, the length of the lesion, lesion located on the proximal left anterior descending artery, the degree of residual stenosis post-angioplasty (assessed by angiography or by intravascular ultrasound) have all been evoked as being classically related to restenosis. However, our perception of the restenosis phenomenon has been dramatically changed by the demonstration of the efficacy and security of active stents. Even in so-called "at risk" populations, the use of active stents is rarely followed by restenosis. In this way, the classic risk factors for restenosis have now become arguments in favour of the implantation of an active stent. As long as budgetary constraints limit the use of active stents to patients said to be "at risk of restenosis", this population, quite paradoxically, will have a more favourable outcome than so-called "low risk" patients, in whom "ordinary" non-active stents will continue to be used.

Clinical outcome of percutaneous coronary intervention with antecedent mutant t-PA administration for acute myocardial infarction

OBJECTIVE

We investigated the acute-phrase and chronic-phase outcomes of patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) with or without antecedent mutant tissue-type plasminogen (t-PA) administration.

METHODS

Thirty-nine patients with a first AMI within 6 hours of onset were randomly assigned to the treatment group (1,600,000 IU IV monteplase, n = 19) or the nontreatment group (n = 20), followed by PCI. Clinical outcomes were then evaluated.

RESULTS

Patient characteristics did not differ between the 2 groups. A significantly higher number of patients in the monteplase group achieved Thrombolysis In Myocardial Infarction trial (TIMI) grade 2 flow or more at the first angiography (84.2% vs 40.0%; P <.005), reduced number of devices (1.44 vs 1.80 devices, P <.05), and reduced procedure times (59.7 vs 86.7 minutes; P <.01), with no differences in peak creatine kinase and rates of major complications and no reflow or distal embolization. Observation over an average of 5.5 months revealed a tendency toward lower target lesion revascularization rates in the monteplase group (17.6% vs 31.6%) but no intergroup difference in rates of major complications. Pretreatment quantitative coronary angioplasty only showed a significant difference in minimal lumen diameter and percent diameter stenosis in the acute phase (1.13 mm in the monteplase group vs 0.66 mm in the nontreatment group, 57.0% vs 73.0%; P <.05). (99m)Tc-QGS (quantitative electrocardiographically gated single-photon emission computed tomographic scintigraphy) showed no intergroup differences in left ventricular end-diastolic volume index, end- systolic volume index, and ejection fraction in the acute and chronic phases.

CONCLUSIONS

Our results suggest that PCI with antecedent mutant t-PA for AMI not only accelerates reperfusion, thereby facilitating PCI, but also attenuates restenosis in the chronic phase.

Clinical evaluation of coronary lesion characteristics in acute myocardial infarction

Coronary lesion instability at the onset of acute myocardial infarction (AMI) was evaluated. The mechanism of AMI has been considered to be coronary lesion instability with occlusive thrombus, although more than one half of AMI occurs in clinically stable patients. A total of 313 AMI patients treated by primary percutaneous transluminal coronary angioplasty with provisional stenting (rate, 41%) were studied. They were divided into 2 groups: group 1A (n = 211), without unstable angina before AMI onset, and group 1B (n = 102), with unstable angina before onset. Moreover, angina patients treated similarly were studied: group 2A (n = 180), with stable angina, and group 2B (n = 204), with unstable angina. Coronary lesion instability at AMI onset was also predicted by C-reactive protein (CRP) levels within 6 hours after onset, before they were affected by myocardial damage. The incidence of repeated AMI and/or target vessel revascularization was 1.9% in group 1A, 7.8% in 1B (p=0.035), 1.7% in 2A, and 5.9% in 2B (p=0.043). Event-free survival curves were consistent with each other in groups 1A and 2A and in groups 1B and 2B. CRP levels on admission were 2.0 +/- 1.7 mg/L in group 1A, 3.3 +/- 4.8 mg/L in group 1B (p<0.001), 2.1 +/- 1.7 mg/L in group 2A, and 3.4 +/- 4.7 mg/L in group 2B (p<0.001). Thus coronary lesion characteristics at AMI onset appeared to be similar in groups 1A and 2A and in groups 1B and 2B. A substantial number of patients have stable culprit lesions at the onset of AMI.

Safety of coronary stenting early after thrombolysis in patients with acute myocardial infarction: one- and six-month clinical and angiographic evolution

To determine the feasibility and safety of early posthrombolysis coronary stenting and the incidence of further reocclusion, we followed 99 consecutive patients with acute myocardial infarction thrombolyzed with rt-PA 2.0 +/- 0.8 hr after onset. Culprit artery was stented 14.0 +/- 7.0 hr after thrombolysis. All patients underwent clinical and angiographic follow-up at 1 and 6 months. Angiographic success was achieved in 99% of cases. Neither major cardiac events nor bleeding or vascular complications occurred during hospital stay. At 30 days, no events occurred and normal flow persisted in all stented arteries. At 6 months, only one artery reoccluded (1%), resulting in a nonfatal reinfarction. Restenosis rate was 21%. Contribution of the infarcted area to left ventricular function significantly increased from baseline to 30-day and to 6-month evaluations. Thus, early posthrombolysis stenting is a safe strategy with a low reocclusion rate, which seems to allow functional recovery of the infarcted area. Further studies are necessary to define its impact on survival and cost-effectiveness.

Intravascular ultrasound-guided stenting in long lesions: an insight into possible mechanisms of restenosis and comparison of angiographic and intravascular ultrasound data from the MUSIC and RENEWAL trials

The high restenosis rates in long stents may be related to suboptimal stent deployment. In an attempt to understand the potential components associated with restenosis in long stents, this study compares angiographic and intravascular ultrasound (IVUS) data from the MUSIC and RENEWAL studies where IVUS was used to optimize stent deployment in short (< 15 mm) and long (> 20 mm) coronary lesions, respectively. The RENEWAL study, a randomized trial, compared the NIR stent and Wallstent in long (> 20 mm) coronary lesions and used on-line visual IVUS criteria to optimize stent expansion. Detailed analysis of IVUS data was performed off line. Angiographic and IVUS data from this study was compared to that from the MUSIC study. Initial stent deployment was deemed optimal by the operator after visual angiographic and IVUS assessment in 50 of 70 lesions. In the remaining 20 lesions further balloon inflations were required to optimize stent apposition that led to an average gain in minimal in-stent luminal area (MISA) of 15.9% (P < 0.01). Off-line IVUS data analysis showed that the number reaching "MUSIC criteria" for optimal stent deployment preredilatation was 8 (11.4%) of 70 and 14 (20%) of 70 postredilatation. The ratio of MISA/MRAprox (mean proximal reference area) was 0.69 in RENEWAL. At 6-month follow-up, the angiographic restenosis rate in RENEWAL was 36% and target lesion revascularization (TLR) rate was 7.8%, compared with MUSIC's 9.7% and 4.5%, respectively. In conclusion, angiographic assessment of stent deployment in long lesions is limited. On-line visual IVUS with further balloon inflations to improve stent apposition led to a significant gain in MISA, but the MISA/MRAprox ratio remained suboptimal. Therefore, suboptimal stent deployment due to constraint by lesion resistance may be an important mechanism underlying the high restenosis rates in long stents.

A randomised trial of endoluminal reconstruction comparing the NIR stent and the Wallstent in angioplasty of long segment coronary disease: results of the RENEWAL Study

BACKGROUND

The role of coronary stents in reducing the incidence of acute complications and late restenosis after angioplasty has been established in randomized studies focusing on simple, short coronary lesions. The development of long coronary stents has provided a safe and predictable means of treating long coronary lesions, but this carries with it a higher risk of restenosis. By comparing the outcome of treating long lesions with two different stent types, we aimed to assess the influence of stent design rather than the nature of long lesions per se on the relatively high restenosis rates in this subgroup.

METHODS

This study was designed to assess procedural complications and 6-month restenosis rates in a randomized trial comparing a slotted tube stent with a self-expanding stent for the treatment of long coronary lesions. Randomization of vessels to either stent occurred after successful balloon angioplasty. Intravascular ultrasound (IVUS) was used to assess and optimize stent deployment. The patients were restudied angiographically and by IVUS at 6 months.

RESULTS

A total of 82 patients (85 vessels) were recruited (slotted tube stent, n = 44 vessels; self-expanding stent, n = 41 vessels). Successful deployment occurred in 41 (100%) of 41 of the self-expanding stent group and 41 (93%) of 44 of the slotted tube stent group. There was no difference in lesion length between the two groups (slotted tube stent, 26.6 +/- 6.9 [SD] mm; self-expanding stent, 28.7 +/- 9.8 [SD] mm; P = .2), but the mean length of the self-expanding stent was greater than that of the slotted tube stent (41.6 +/- 18.8 [SD] mm vs 35.4 +/- 16.2 [SD] mm, respectively; P < .05). There was no significant difference in the rate of major events between the two groups at 6-month follow-up. The angiographic restenosis rate at follow-up was less in the slotted tube stent group, but this did not reach statistical significance (26% vs 46%, respectively; P = .1) and the target lesion revascularization rate was similar for both groups (7.9% vs 7.7%, respectively; P = .8). IVUS assessment of plaque/stent ratios suggested a greater plaque burden in the self-expanding stent compared with the slotted tube stent at follow-up (0.42 +/- 1.2 [SD] vs 0.3 +/- 0.08 [SD]), but this was not statistically significant (P = .1).

CONCLUSIONS

Long stents can be safely and successfully deployed in long segment coronary disease, with an acceptable 6-month target lesion revascularization rate. Our results showed a trend toward lower angiographic restenosis and a lesser in-stent plaque burden at follow-up in the slotted tube stent compared with the self-expanding stent. This suggests that stent design may influence the restenotic process in long coronary lesions.

Long-term outcome in patients with unstable angina treated by coronary balloon angioplasty

Comparison of balloon angioplasty results in 472 patients with stable angina (SA) and 158 patients with unstable angina (UA) in 5-year follow-up is reported. Clinical success rate did not differ significantly, while periprocedural complications rate was higher in UA group (22.3 vs. 11.1%, P<0.001). During follow-up UA patients demonstrated higher: restenosis rate (48.5 vs. 30.4%, P<0.001), incidence of myocardial infarction (8.8 vs. 3.0%, P=0.004), although cardiac mortality did not differ significantly (2.2 vs. 1.6%). Reintervention rate in patients with unstable angina resultant from restenosis or significant artherosclerosis progression in coronary vessels, or originating from both of them, was also higher (53.7 vs. 34.1%, P<0.001). Event-free survival was significantly lower in UA patients (43.4 vs. 61.3%, P=0.02). The uni- and multivariate analysis proved that unstable angina was an independent risk factor in restenosis, re-intervention and cardiac events rate, despite perceptible differences in the baseline characteristics. Sub-group analysis of UA patients according to Braunwald classification revealed lower success rate and higher incidence of myocardial infarction during follow-up in post-infarction angina (class C), whereas new onset, no-rest angina (class I) had higher event-free survival in comparison with rest angina (classes II and III).

CONCLUSIONS

UA patients treated by balloon angioplasty had higher periprocedural complications rate, as well as restenosis and re-intervention rate. Despite higher cardiovascular events rate during 5-year follow-up in UA group, survival rate in both groups was high and cardiac mortality did not differ significantly. Unstable angina constitutes a strong independent risk factor in adverse long-term outcome.

Lipoprotein (a) and anticardiolipin antibodies are risk factors for clinically relevant restenosis after elective balloon percutaneous transluminal coronary angioplasty

Recent reports have shown the importance of new risk factors for cardiovascular disease. We investigated the relationship between Lp(a), fibrinolytic parameters and anticardiolipin antibodies (aCL) and the occurrence of clinical recurrence owing to restenosis after elective balloon percutaneous transluminal coronary angioplasty (PTCA) without stenting. In 167 patients, undergoing PTCA, Lp(a) plasma levels, aCL, euglobulin lysis time (ELT), plasminogen activator inhibitor-1 (PAI-1) activity and tissue-type plasminogen activator (t-PA) plasma levels were evaluated before the procedure. During follow-up 29 patients underwent clinical recurrence due to restenosis. Lp(a) levels were significantly higher in patients with restenosis in comparison to those without (P<0.05); an earlier restenosis was observed in patients with Lp(a) values >450 mg/L. Kaplan-Meier survival estimate showed an earlier occurrence of restenosis in patients with base-line Lp(a)>300 mg/l associated with aCL positivity. High Lp(a) plasma levels play a role in the occurrence of clinical recurrence due to restenosis after elective balloon PTCA without stenting; the association with aCL accelerates the development of restenosis.

The pre-procedural platelet state predicts clinical recurrence after coronary angioplasty

Percutaneous transluminal coronary angioplasty is an established therapy for coronary artery disease, but restenosis still occurs at a rate of 25%-40%. The aim of this study was to investigate the acute effect of percutaneous transluminal coronary angioplasty on platelet function and the relationship between platelet function and clinical recurrence. Spontaneous platelet aggregation was assessed before and after successful coronary angioplasty in 155 patients (120 men, 35 women). Patients were followed for a mean time of 20 months; follow-up angiography was performed only in patients with clinical recurrence. In 122 of 155 patients (79%) a significant increase in spontaneous platelet aggregation was observed immediately after coronary angioplasty. Baseline spontaneous platelet aggregation in platelet-rich plasma was significantly lower in patients with clinical recurrence than in those without (P<0.05). Kaplan-Meier event-free survival estimate showed a significant difference in clinical recurrence between patients with spontaneous platelet aggregation in platelet-rich plasma below and above the first quintile (P<0.05) with a relative risk of 2.5. In conclusion. these results indicate that percutaneous transluminal coronary angioplasty enhances spontaneous platelet aggregation and that the platelet state before coronary angioplasty affects the risk of clinical recurrence after the procedure.

Long-term outcome in patients treated by intracoronary stenting with ticlopidine and aspirin, and deleterious prognostic role of unstable angina pectoris

Compared with stable clinical conditions, unstable angina carries an increased risk of immediate and delayed cardiac adverse events after balloon coronary angioplasty. The influence of stent use in reducing these differences remains unknown. We analyzed the early (30 days) and late outcome of a cohort of 459 consecutive patients who underwent stent placement with ticlopidine and aspirin as antithrombotic regimen according to the presence (group 1, n = 151) or absence (group 2, n = 308) of unstable angina at rest (Braunwald classes II and III). Group 1 patients were older and more likely to be current or former smokers. In group 2, prior myocardial infarction was more frequent. Procedural, in-hospital results, and early outcome were similar in the 2 groups. However, over the long term, the incidence of myocardial infarction (11% vs 6%, p <0.04), target lesion revascularization (19% vs 13%, p <0.04), or any revascularization (30% vs 20%, p <0.01) was significantly higher in group 1. Kaplan-Meier probabilities of survival without myocardial infarction (85% vs 91%, p <0.05), survival without revascularization of the target lesion (73% vs 83%, p <0.01), survival without any revascularization (65% vs 77%, p <0.006), and survival without any events (61% vs 73%, p <0.009) were significantly worse in group 1. In addition, Cox multivariate analysis showed that unstable angina at rest was an independent predictor of target lesion revascularization, of survival without any revascularization, and without any events. Thus, unstable angina at rest remains an adverse prognostic indicator in patients treated with intracoronary stents, particularly with regard to subsequent requirement of revascularization procedures and event-free survival.

Angiographic and clinical outcome of a new self-expanding intracoronary stent (RADIUS): results from multicenter experience in Japan

The RADIUS coronary stent featuring a multisegmented slotted tube design and self-expanding nitinol delivery system has a high radial force and flexibility, uniform expansion, and contours to the shape of the vessel. Successful stent deployment was achieved in 104 stable angina patients (106 lesions; 44% LAD, 19% circumflex, and 37% RCA). Mean minimal lumen diameter (MLD) increased from 0.77 +/- 0.46 mm to 2.88 +/- 0.61 mm and mean percent diameter stenosis (% DS) decreased from 73 +/- 14% to 6 +/- 13% immediately after the procedure. At 6-month follow-up, two patients (2%) underwent urgent target revascularization, and cerebral bleeding occurred in one patient (1%). Angiographic follow-up was performed in 94 lesions (89%) and mean MLD and mean % DS were 2.08 +/- 0.92 mm and 30% +/- 24%, respectively. Stent restenosis (>50% diameter stenosis at follow-up) was observed in 16 (17%) of all lesions. The high success rate for stent deployment, low incidence of major adverse cardiac event, and lower restenosis rate after stent implantation indicate that the RADIUS stent is useful for coronary intervention.

A subgroup analysis of the Scripps Coronary Radiation to Inhibit Proliferation Poststenting Trial

INTRODUCTION

In the Scripps Coronary Radiation to Inhibit Proliferation Poststenting (SCRIPPS) Trial, 192Ir significantly reduced angiographic, ultrasonographic, and clinical endpoints of restenosis. The objective of this analysis was to quantitate the impact of patient, lesion and technical characteristics on late angiographic outcome.

METHODS

Patients with restenotic, stented coronary lesions were randomized to receive either 192Ir or placebo sources. Late luminal loss and loss index were calculated for several patient subgroups, including patients with diabetes, in-stent restenosis, multiple previous percutaneous transluminal coronary angioplasty (PTCA) procedures, longer lesion lengths, saphenous vein grafts, small vessel diameters, and minimum dose exposures < 8.00 Gy. Two-factor analysis of variance was used to test for an interaction between patient characteristics and treatment effect.

RESULTS

In the treated group, late loss was particularly low in patients with diabetes (0.19 mm), in-stent restenosis (0.17 mm), reference vessel diameters < 3.0 mm (0.07 mm), and patients who received a minimum radiation dose to the entire adventitial border of at least 8.00 Gy. The loss index in each of these subgroups was similarly low at -0.02, 0.03, -0.02, and 0.03, respectively. By 2-factor analysis of variance, a significant interaction between subgroup characteristic and treatment effect (late loss) was found in patients with in-stent restenosis (p = 0.035), and patients receiving a minimum dose of 8.00 Gy to the adventitial border (p = 0.009).

CONCLUSION

In this pilot study, patient characteristics associated with a more aggressive proliferative response to injury appeared to confer an enhanced response to radiotherapy. Furthermore, a dose threshold response to 192Ir was found with an enhanced response occurring when the entire circumference of the adventitial border was exposed to at least 8.00 Gy.

Long-term (10-year) outcome in patients with unstable angina pectoris treated by coronary balloon angioplasty

OBJECTIVES

We sought to examine completed 10-year survival and event-free survival in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty.

BACKGROUND

Patients with unstable angina are at increased risk for recurrent acute coronary events.

METHODS

The study included 208 consecutive patients (133 with stable and 75 with unstable angina pectoris) undergoing angioplasty from 1984 to 1986. The balloon crossed the lesion in 185 patients (121 with stable and 64 with unstable angina pectoris). Angioplasty was performed in patients with unstable angina pectoris 12+/-15 days (median 8) after symptom onset. Patients with unstable angina pectoris were classified retrospectively into Braunwald class I (n=3), class II (n=20), class III (n=28), class B (n=52) and class C (n=12). Follow-up data were obtained from hospital charts, telephone interview and official death certificates where applicable. The study had >80% power to detect a clinically significant 20% difference in survival and a 20% difference in event-free survival between the stable and unstable patient groups.

RESULTS

Despite similar baseline characteristics, early (40-day) mortality was slightly higher in patients with unstable angina (4.7% [3 of 64 patients] vs. 0.8% [1 of 121 patients], p=NS). Long-term outcome was not different, because survival curves were parallel thereafter (10-year survival was 83% for those with stable and 77% for those with unstable angina, p=NS). Survival free of myocardial infarction or coronary artery bypass graft surgery at 10 years was 53% in patients with stable and 47% in patients with unstable angina (p=NS), and survival free of infarction, bypass surgery or repeat angioplasty was 32% for both groups at 10 years. In patients with Braunwald class III unstable angina, 10-year survival was 80%, as compared with 85% in other patients with unstable angina, due to the early hazard (p=NS). Survival and event-free survival were similar in patients who had had a recent myocardial infarction (Braunwald class C) and in patients with acute electrocardiographic changes. Repeat hospital admissions were not more frequent in patients with unstable angina (3.1+/-3.5 vs. 3.0+/-2.6, p=NS).

CONCLUSIONS

Ten-year survival and event-free survival were similar in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty, with no evidence of an increased rate of recurrent cardiovascular events in the unstable group.

Antiphospholipid antibodies: a new risk factor for restenosis after percutaneous transluminal coronary angioplasty?

Antiphospholipid antibodies (aPL) have been found to be associated with arterial and venous thrombosis. Percutaneous transluminal coronary angioplasty (PTCA) is an established therapy for ischaemic heart disease (IHD), which is still affected by restenosis at a rate of 20-30%. This study was aimed at investigating the possible role of aPL in restenosis after PTCA. In sixty consecutive IHD patients, aPL (lupus anticoagulant -LA- and anticardiolipin antibodies -aCL) and markers of haemostatic activation were investigated before PTCA, and patients were followed up for restenosis. No infections, autoimmune disease or treatment by drugs that may alter aPL levels occurred in any of the patients. aPL were found in 15/60 patients: aCL in 7/60, LA in 5/60 and aCL and LA in 3/60. No statistically significant difference was found between aPL negative and aPL positive patients in pre PTCA plasma levels of prothrombin activation fragment (F1+2) 1.4 nmol/l (0.3-5.71) vs 1.4 nmol/l (0.9-4.0), thrombin-antithrombin complex (TAT) 4.0 microg/l (1.1-34.2) vs 5.2 microg/l (2.1-60.0), D-dimer (DD) 25 ng/ml (2-515) vs 44 ng/ml (2-160) or plasminogen activator inhibitor activity (PAI) 4.8 IU/ml (2.5-36.4) vs 4.4 IU/ml (2.5-13.4). Restenosis was observed in 13/60 patients (7/45-15% - aPL negative and 6/15-40% - aPL positive patients) who underwent angiographic tests after PTCA because of recurring angina or positive exercise test. Restenosis occurred after 2.2 months (0.5-3) in aPL positive patients and after 3.5 months (1-12.8) in aPL negative. These results suggest that 1) restenosis with recurrent ischaemia occurs more frequently in aPL positive than in aPL negative patients, 2) in aPL positive patients restenosis occurs earlier, and 3) the presence of aPL is not associated with hypercoagulability.

Predictors of restenosis after coronary stent implantation

OBJECTIVES

We sought to determine predictors of restenosis after coronary stenting (CS) in a consecutive series of patients.

BACKGROUND

Although stenting in highly selected patient groups reduces restenosis, the results of stenting in a heterogeneous patient group and the effects of clinical and procedural factors on stent restenosis are currently unclear.

METHODS

We analyzed the 6-month angiographic outcome of 500 lesions in 463 consecutive patients undergoing successful CS. Clinical, qualitative and quantitative angiographic variables were correlated with restenosis assessed as both a binary and a continuous variable.

RESULTS

Restenosis, defined as the presence of >50% diameter stenosis in the dilated segment, was present in 105 (26%) of the 405 lesions with angiographic follow-up. The mean late lumen loss during the follow-up period was 0.79+/-0.64 mm. Implantation of multiple stents (p < 0.0001) and a high acute gain (p < 0.0002) were independently associated with a higher late lumen loss. In contrast, the use of high inflation pressure (p < 0.02) and Palmaz-Schatz stents (p < 0.005) was independently associated with a lower late lumen loss. When restenosis was defined as a qualitative variable, implantation of multiple stents (p < 0.001), stenosis length (p < 0.01), small reference diameter (p < 0.02) and stent type other than Palmaz-Schatz (p < 0.01) were independent predictors of restenosis. None of the clinical variables tested was associated with restenosis.

CONCLUSIONS

Coronary stenting in an unselected patient group is associated with an acceptable restenosis rate. Although some risk factors were identified, the risk of restenosis was not related to most of the variables tested. This suggests that the superiority of CS over balloon angioplasty, in terms of restenosis, might also apply to subgroups of patients that were not included in the recent randomized studies.

Conjugated equine estrogens inhibit progression of atherosclerosis but have no effect on intimal hyperplasia or arterial remodeling induced by balloon catheter injury in monkeys

OBJECTIVES

This study sought to determine the effects of estrogen treatment on atherosclerosis progression and the proliferative and structural responses of the atherosclerotic arteries to injury.

BACKGROUND

Estrogen treatment suppresses the intimal response to arterial injury in nonatherosclerotic rodents and rabbits and inhibits the in vitro proliferation of smooth muscle cells. However, the effect of estrogen on the response of atherosclerotic arteries to transmural injury, as occurs in balloon catheter angioplasty in humans, is unknown.

METHODS

Forty-six ovariectomized cynomolgus monkeys were fed an atherogenic diet for 30 months; 25 received 175 microg/day of conjugated equine estrogens, and 21 served as untreated control animals. All animals underwent balloon catheter injury of the left iliac artery. Subsets of animals underwent a necropsy study at 4, 7, 14 and 28 days after injury; injured and contralateral (uninjured) arteries were pressure-fixed and evaluated morphometrically.

RESULTS

Estrogen treatment resulted in a 37% decrease (p < 0.05) in atherosclerosis (plaque area) in the uninjured artery. In response to injury, arterial cell proliferation increased at days 4 and 7, and intimal area was increased two- to threefold at day 28 (p < 0.05). Although estrogen treatment resulted in a trend toward decreased arterial cell proliferation at day 4, there was evidence of increased cell proliferation in both media and intima at day 7 (p < 0.05). However, there was no effect of estrogen treatment on intimal area or indexes of arterial remodeling in the injured artery at day 28 (p > 0.4). CONCLUSIONS. In contrast to previous studies of nonatherosclerotic animals, the results indicate that in the circumstance of transmural injury to arteries of primates with preexisting atherosclerosis, estrogen does not suppress arterial neointimal or structural responses to injury.

Restenosis after coronary stenting in current clinical practice

BACKGROUND

Randomized trials have demonstrated that planned coronary stenting may lower restenosis rate in patients with de novo short lesions. In a prospective study we sought to determine the frequency of restenosis, reocclusion, and adverse cardiovascular events after coronary stenting in a series of 258 consecutive nonselected patients, including those with complex lesions not fulfilling past and ongoing randomized trial criteria for stent implantation.

METHODS

Criteria for stenting were as follows: (1) dissection associated with occlusion or threatened closure, (2) a residual percentage stenosis > 30% or nonocclusive dissection, (3) restenotic lesion or chronic total occlusion.

RESULTS

In most cases (89%) the target lesion had two or more unfavorable morphologic characteristics, whereas only 11% of target lesions could be classified as type A or B1 lesions. Overall, the 6-month restenosis rate was 23%. By use of subgroup analysis restenosis rate was found to range widely, from 11% to 46%. With multivariate analysis, only four variables were found to be independently related to restenosis: age > 63 years (odds ratio [OR] = 2.651, p = 0.011), female sex (OR = 3.807, p = 0.002), lesion length > 12 mm (OR 3.185, p = 0.002), and type C lesion (OR 2.527, p = 0.014).

CONCLUSIONS

Results from randomized trials on coronary stenting cannot be extrapolated to current clinical practice because most of the treated lesions do not fulfill the criteria adopted in these studies for stent implantation. The restenosis rate is nearly four times greater for long and complex lesions treated by multiple stent implantation as compared with simple lesions, and additional studies need to be performed to evaluate the efficacy of stenting on these lesions.

Predictive factors of restenosis after coronary stent placement

OBJECTIVES

The objective of this study was to identify clinical, lesional and procedural factors that can predict restenosis after coronary stent placement.

BACKGROUND

Coronary stent placement reduces the restenosis rate compared with that after percutaneous transluminal coronary angioplasty (PTCA). However, restenosis remains an unresolved issue, and identification of its predictive factors may allow further insight into the underlying process.

METHODS

All patients with successful coronary stent placement were eligible for this study unless they had had a major adverse cardiac event during the 1st 30 days after the procedure. Of the 1,349 eligible patients (1,753 lesions), follow-up angiography at 6 months was performed in 80.4% (1,084 patients, 1,399 lesions). Demographic, clinical, lesional and procedural data were prospectively recorded and analyzed for any predictive power for the occurrence of late restenosis after stenting. Restenosis was evaluated by using three outcomes at follow-up: binary restenosis as a diameter stenosis > or =50%, late lumen loss as lumen diameter reduction and target lesion revascularization (TLR) as any repeat PTCA or coronary artery bypass surgery involving the stented lesion.

RESULTS

Multivariate analysis demonstrated that diabetes mellitus, placement of multiple stents and minimal lumen diameter (MLD) immediately after stenting were the strongest predictors of restenosis. Diabetes increased the risk of binary restenosis with an odds ratio (OR) [95% confidence interval] of 1.86 [1.56 to 2.16] and the risk of TLR with an OR of 1.45 [1.11 to 1.80]. Multiple stents increased the risk of binary restenosis with an OR of 1.81 [1.55 to 2.06] and that of TLR with an OR of 1.94 [1.66 to 2.22]. An MLD <3 mm at the end of the procedure augmented the risk of binary restenosis with an OR of 1.81 [1.55 to 2.06] and that of TLR with an OR of 2.05 [1.77 to 2.34]. Classification and regression tree analysis demonstrated that the incidence of restenosis may be as low as 16% for a lesion without any of these risk factors and as high as 59% for a lesion with a combination of these risk factors.

CONCLUSIONS

Diabetes, multiple stents and smaller final MLD are strong predictors of restenosis after coronary stent placement. Achieving an optimal result with a minimal number of stents during the procedure may significantly reduce this risk even in patients with adverse clinical characteristics such as diabetes.

Thromboxane A2 induces cell signaling but requires platelet-derived growth factor to act as a mitogen

This study investigates thromboxane A2-induced cell signaling and mitogenesis of bovine coronary artery smooth muscle cells. The thromboxane mimetic U 46619 [(15S)-hydroxy-11,9-(epoxymethano) prosta-5Z,13E-dienoic acid] (10 microM) stimulated [Ca2+]i signals, phosphorylation of MAP kinase (mitogen-activated protein kinase), and expression of c-fos mRNA in smooth muscle cells. In contrast, no stimulation of DNA synthesis or cell proliferation by U 46619 was observed. However, platelet-derived growth factor-BB (20 ng/ml)-induced mitogenesis was potentiated by U 46619. Similar results were obtained with I-BOP [1S-(1 alpha,2 beta(5Z),3 alpha(1E,3R*), 4 alpha)]-7-[3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl)-7-oxabicyclo [2.2.1] heptan-2-yl]-5-heptenoic acid]. These potentiating effects were abrogated by a specific thromboxane receptor antagonist, suggesting that the potentiation of platelet-derived growth factor-BB-induced smooth muscle cell mitogenesis by U 46619 and I-BOP was mediated by thromboxane receptors. It is concluded that thromboxane A2 generated by blood platelets at the site of vessel injury induces cell signaling in smooth muscle cells but acts as a mitogen only in the presence of growth factor(s).

Anti-atherogenicity in women does not prevent restenosis after balloon angioplasty

To test the hypothesis that anti-atherogenicity in women exerts beneficial effects to prevent restenosis formation after coronary angioplasty, we studied 493 men (988 lesions) and 81 women (159 lesions), aged 40-60 years, who had undergone successful balloon angioplasty and had follow-up angiography, 4.9 +/- 4.1 months later. We compared the extent of restenosis between men and women, and between pre- and post-menopausal women, which was assessed by a categorical definition of restenosis (more than 50% diameter stenosis at follow-up) and by percent diameter measured immediately after angioplasty and at follow-up. Hypertension was more frequent in women and a significantly lower percentage of women smoked. In women, the levels of total cholesterol and low-density lipoprotein cholesterol were higher. The location of dilated lesions, frequency of angioplasty for lesions with chronic total occlusion, and frequency of emergency angioplasty in patients with unstable angina or acute myocardial infarction were similar in men and women. Restenosis formation, estimated by the categorical definition or percent diameter, did not differ between men and women, or between pre- and post-menopausal women. Menopausal status or sex was not an independent predictor of restenosis by multivariate analysis. Thus, the benefit of anti-atherogenicity in women does not play an important role in preventing restenosis after coronary angioplasty.

Unstable angina. Strategies to minimize myocardial injury

The primary goals in treatment of unstable angina are to relieve pain and prevent or limit myocardial infarction or ischemia. Patients with distinct, rapid progression of their usual angina pattern should be admitted to a coronary care unit and given heparin and intravenous nitrates as well as aspirin. Cardioselective beta blockers should also be administered when there are no contraindications. Intravenous thrombolytic agents are indicated in patients with objective evidence of ischemia who fit criteria for this therapy. However, thrombolysis is not advocated for routine treatment of unstable angina. Percutaneous transluminal coronary angioplasty or coronary artery bypass grafting should be considered--depending on the location, age, and morphology of the culprit lesion and the degree of left ventricular dysfunction--in patients who have refractory or recurrent ischemia despite aggressive medical therapy. However, in general, high-technology interventions are not a substitute for long-term regimens, such as risk-factor and lifestyle modification, daily aspirin, and pharmacologic therapies aimed at maximizing cardiac function.

Management of restenosis after coronary intervention

Coronary restenosis has proven to be the "Achilles heel" of percutaneous coronary interventions, frequently leading to repeated procedures. The pathogenesis of restenosis can be divided into four phases: early elasic recoil (hours to days), mural thrombus formation (hours to days), neointimal proliferation and extracellular matrix formation (weeks), and chronic geometric arterial changes (months). Restenosis is device nonspecific except for intravascular stents, which can eliminate elastic recoil and prevent geometric vessel changes, leading to decreased restenosis. Of all antithrombotics tried so far, only an inhibitor of the platelet IIb/IIIa integrin, which may lead to early vessel wall passivation, has shown reduction of clinical restenosis. Trapidil (antiproliferative agent) and angiopeptin (somatostatin analog) have also resulted in improved restenosis rates. The field of local drug delivery is currently under investigation in association with radiation or molecular therapy. The current specific target of these approaches is the neointimal proliferation, especially because this is the most dominant mechanism of restenosis after stent placement. Evaluation of these novel methods is complex and interrelates the delivery system with the therapeutic agent administered. However, they provide the means for very specific and timely interruption of the pathogenic process that may lead to better understanding and, ultimately, elimination of restenosis.