Optimum percutaneous transluminal coronary angioplasty compared with routine stent strategy trial (OPUS-1): a randomised trial

Reverse J-curve relation between diastolic blood pressure and severity of coronary artery lesion in hypertensive patients with angina pectoris

The existence of the J-curve in hypertension treatment remains controversial. The major question is whether the increase in mortality from coronary disease is induced by the lowering of blood pressure (BP) or by the severity of underlying coronary artery disease. We recruited patients with a history of hypertension (systolic BP (SBP) >160 mmHg and/or diastolic BP (DBP) >90 mmHg) and a diagnosis of angina pectoris with angiographically confirmed coronary artery lesion. The relationship among the treated levels of SBP and DBP, the severity of coronary artery lesion, and the clinical consequences were investigated. Among the 234 enrolled patients, 115 experienced further events, 19 of which were serious. There were no significant differences in the average BP of patients with and those without events, but the coronary severity indices (CSI) were significantly greater in patients with events. As a function of DBP from < or = 74 to 105 < or = mmHg, there was a positive association with the incidence of serious events, and a reversed J-curve in CSI with a nadir at 95-104 mmHg. A similar relationship was observed in SBP, but a potentially unfavorable outcome was suggested in the lowest SBP range of < or = 124 mmHg. In conclusion, there was no J-curve for DBP in hypertensive patients with angina pectoris; rather, the lower the DBP, the better was the prognosis. Interestingly, the severity of coronary lesion is in a reversed J-curve relation with DBP, suggesting that high BP plays a critical role in serious events in hypertensive patients with moderate coronary artery lesions.

A randomized comparison of the value of additional stenting after optimal balloon angioplasty for long coronary lesions: final results of the additional value of NIR stents for treatment of long coronary lesions (ADVANCE) study

OBJECTIVES

We sought to investigate the clinical benefit of additional stent implantation after achieving an optimal result of balloon angioplasty (BA) in long coronary lesions (>20 mm).

BACKGROUND

Long coronary lesions are associated with increased early complications and late restenosis after BA. Stenting improves the early outcome, but stent restenosis is also related to both lesion length and stent length.

METHODS

A total of 437 patients with a single native lesion 20 to 50 mm in length were included and underwent BA, using long balloons matched to lesion length and vessel diameter (balloon/artery ratio 1.1) to achieve a diameter stenosis (DS) <30% by on-line quantitative coronary angiography (QCA). "Bail-out stenting" was performed for flow-limiting dissections or >50% DS. Patients in whom an optimal BA result was achieved were randomized to additional stenting (using NIR stents) or no stenting. The primary end point was freedom from major adverse cardiac events (MACE) at nine months, and core laboratory QCA was performed on serial angiograms.

RESULTS

Bailout stenting was necessary in 149 patients (34%) and was associated with a significantly increased risk of peri-procedural infarction (p < 0.02). Among the 288 randomized patients, the mean lesion length was 27+/-9 mm, and the vessel diameter was 2.78+/-0.52 mm. The procedural success rate was 90% for the 143 patients assigned to BA alone (control group), as compared with 93% in the 145 patients assigned to additional stenting (stent group), which resulted in a superior early minimal lumen diameter (0.54 mm, p < 0.001) and led to reduced angiographic restenosis (27% vs. 42%, p = 0.022). Freedom from MACE at nine months was 77% in both groups.

CONCLUSIONS

A strategy of provisional stenting for long coronary lesions led to bailout stenting in one-third of patients, with a threefold increase in peri-procedural infarction. Additional stenting yielded a lower angiographic restenosis rate, but no reduction in MACE at nine months.

Cost-effectiveness of coronary stenting in acute myocardial infarction: results from the stent primary angioplasty in myocardial infarction (stent-PAMI) trial

BACKGROUND

Although several randomized trials have demonstrated that coronary stenting improves angiographic and clinical outcomes for patients with acute myocardial infarction (AMI), the cost-effectiveness of this practice is unknown. The objective of the present study was to evaluate the long-term costs and cost-effectiveness (C/E) of coronary stenting compared with primary balloon angioplasty as treatment for AMI. Methods and Results- Between December 1996 and November 1997, 900 patients with AMI were randomized to undergo balloon angioplasty (PTCA, n=448) or coronary stenting (n=452). Detailed resource utilization and cost data were collected for each patient's initial hospitalization and for 1 year after randomization. Compared with conventional PTCA, stenting increased procedural costs by approximately $2000 per patient ($6538+/-1778 versus $4561+/-1598, P<0.001). During the 1-year follow-up period, stenting was associated with significant reductions in the need for repeat revascularization and rehospitalization. Although follow-up costs were significantly lower with stenting ($3613+/-7743 versus $4592+/-8198, P=0.03), overall 1-year costs remained approximately $1000/patient higher with stenting than with PTCA ($20 571+/-10 693 versus 19 595+/-10 990, P=0.02). The C/E ratio for stenting compared with PTCA was $10 550 per repeat revascularization avoided. In analyses that incorporated recent changes in stent technology and pricing, the 1-year cost differential fell to <$350/patient, and the C/E ratio improved to $3753 per repeat revascularization avoided. The cost-utility ratio for primary stenting was <$50 000 per quality-adjusted life year gained only if stenting did not increase 1-year mortality by >0.2% compared with PTCA.

CONCLUSIONS

As performed in Stent-PAMI, primary stenting for AMI increased 1-year medical care costs compared with primary PTCA. The overall cost-effectiveness of primary stenting depends on the societal value attributed to avoidance of symptomatic restenosis, as well as on the relative mortality rates of primary PTCA and stenting.

Quality of life after balloon angioplasty or stenting for acute myocardial infarction. One-year results from the Stent-PAMI trial

OBJECTIVES

The goal of this study was to compare the impact of primary stenting or percutaneous transluminal coronary angioplasty (PTCA) on health-related quality of life (HRQOL) in patients undergoing direct angioplasty for acute myocardial infarction (AMI).

BACKGROUND

Previous studies have demonstrated that coronary stenting reduces clinical and angiographic restenosis compared with PTCA. However, the impact of stenting on HRQOL from the patient's perspective remains unknown.

METHODS

We administered the Seattle Angina Questionnaire and the Medical Outcomes Study Short-form Survey at 1, 6 and 12 months after initial treatment to all North American patients in the Stent-Primary Angioplasty for Myocardial Infarction trial (Stent-PAMI) (n = 509)-a randomized trial comparing primary stenting to conventional PTCA for patients with AMI.

RESULTS

At one month, most HRQOL measures were similar for the two groups, but stent patients reported less bodily pain than PTCA patients (p = 0.03). At six-month follow-up, stenting resulted in significant improvements in several dimensions of HRQOL including reduced anginal frequency and bodily pain as well as improved disease perception (all p < or = 0.03) and a trend towards better anginal stability (p = 0.056). By 12-month follow-up, however, none of these differences remained statistically significant. These differences in HRQOL were largely explained by the greater need for ischemia-driven target-vessel repeat revascularization procedures in PTCA patients during the first six months (16.0% vs. 6.2%, p < 0.001).

CONCLUSIONS

In patients undergoing revascularization for AMI, initial stent placement is associated with improvements in several dimensions of health status during the first six months of follow-up. In the absence of differences in mortality, these findings add to the overall argument in favor of initial stenting in patients treated with mechanical reperfusion for myocardial infarction.

Provisional stenting in the real world: results in 1058 consecutive patients undergoing percutaneous coronary angioplasty

OBJECTIVE: To study a strategy of aggressive coronary balloon angioplasty with provisional stenting in allcomers. In randomized trials, stenting has improved the outcome of patients undergoing coronary intervention. However, whether these results hold up in clinical practice is largely unknown. Furthermore, the results of balloon angioplasty have also improved dramatically. It is therefore essential to evaluate the current results of balloon angioplasty and to assess whether stents are required in all patients. METHODS: The authors prospectively studied the occurrence of death, myocardial infarction (MI) and target lesion revascularization (TLR) of a large consecutive group of patients undergoing aggressive balloon angioplasty with provisional stenting. None of the patients received a platelet glycoprotein IIb/IIIa receptor blocker. The results were compared with the outcome of routine stenting in recent randomized trials. RESULTS: Angioplasty was performed in 1058 patients of whom 369 (34.9%) received a stent. The angiographic success rate was 98.9%. During hospital stay, 4.8% of the patients suffered any cardiac event. At one-year follow-up, death occurred in 1.1%, MI in 3.3%, TLR in 12.4% and any event in 16.7% of the patients. Event-free survival at one-year was 82.3%. These results compare favorably with routine stenting in recent trials. CONCLUSIONS: Aggressive balloon angioplasty with provisional stenting yields excellent results in a general patient population.

The role of acute wall recoil and late restenosis: results of the OCBAS trial (Optimal Coronary Balloon Angioplasty with Provisional Stenting versus Primary Stent)

Early deterioration of minimal luminal diameter immediately after PTCA, has been associated with an increase of late restenosis. Lesions with no early loss after PTCA have a low restenosis rate. Coronary stents reduce restenosis in lesions exhibiting early wall recoil. The purpose of the OCBAS study was to compare two strategies during coronary interventions; provision vs. elective stenting. 116 patients with good PTCA results were randomized to stent (n = 57) or to optimal PTCA (n = 59). After randomization in PTCA group, 13.5% of the patients crossed over to stent due to early loss (provisional stenting). Baseline demographic and angiographic characteristics were similar in both groups of patients. At 7.6 months, 96.6% of the entire population had a follow-up angiographic study; 98.2% in the stent and 94.9% in the PTCA group. Immediate and follow-up angiographic data showed that acute gain was significantly higher in the stent than in the PTCA group (1.95 vs. 1.5 mm; P < 0.03). However, late loss was significantly higher in the stent than the PTCA groups (0.63 +/- 0.59 vs. 0.26 +/- 0.44, respectively; P = 0.01). Hence, net gain with both techniques was similar (1.32 +/- 0.3 vs. 1.24 +/- 0.29 mm for the stent and PTCA groups respectively; P = NS). Angiographic restenosis rate at follow-up (19.2% in stent vs. 16.4% in PTCA; P = NS) and TVR (17.5 in stent vs. 13.5% in PTCA; P = NS) were also similar. Furthermore, event-free survival was 80.8% in the stent versus 83.1% in the PTCA group (P = NS). Overall costs (hospital and follow-up) were US$591,740 in the stent versus US$398,480 in the PTCA group (P < 0.02). The strategy of the PTCA with delay angiogram and provisional stent if early loss occurs, had similar restenosis rate and TVR than universal use of bare stents.

Intravascular-ultrasound-guided percutaneous transluminal coronary angioplasty/provisional stent implantation strategy: impact on long-term clinical follow-up

Two hundred and eighty-four consecutive patients with 438 native coronary artery stenoses were enrolled prospectively in a study of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with provisional stenting: (1) aggressive lesion-site media-to-media balloon-sizing; (2) IVUS-assessment of residual lumen dimensions to identify optimal PTCA results (minimum lumen area = 65% of the average of the proximal and distal reference lumen areas or = 6.0 mm(2) and no major dissection); and (3) liberal stent crossover. Overall, 206 stenoses in 134 patients (47%) were treated with PTCA alone. Reasons for crossover were flow-limiting or lumen-compromising dissections in 28% of patients and suboptimal IVUS minimum lumen area in 72% of patients. At one year, 8% of stenoses in the PTCA group and 16% in the stent crossover group required revascularization. In approximately half of the patients treated using an IVUS-guided aggressive PTCA strategy, stent implantation could be avoided without sacrificing an increase in acute complications or worse clinical outcome.

An introduction to provisional stenting

Provisional or conditional stenting should be defined as the use of stents limited to those conditions and cases in which the operator, despite an aggressive balloon angioplasty technique with large balloons and high pressure, has been unable to obtain a result that ensures optimal chances of early and late patency. The paramount issue is how to discriminate the patients with optimal results after balloon angioplasty for whom additional stent implantation is unlikely to improve or may even worsen long-term outcome. The better results of elective stent implantation in the OPUS study suggest that visual assessment of the PTCA result is not sufficient to detect lesions with suboptimal lumen gain after PTCA. The addition of physiologic parameters (Doppler flow velocity measurements, fractional flow reserve) has improved the results of the provisional stent group, with the best outcome observed when complex lesions and multivessel treatment were included in these studies (FROST, DESTINI). Intravascular ultrasound, although more expensive and time-consuming, has the additional advantage to guide the dilatation strategy.

Achieving optimal results with standard balloon angioplasty: can baseline and angiographic variables predict stent-like outcomes?

OBJECTIVES

To predict which patients might not require stent implantation, we identified clinical and angiographic characteristics associated with repeat revascularization after standard balloon angioplasty.

BACKGROUND

Stents reduce the risk of repeat revascularization but are costly and may lead to in-stent restenosis, which remains difficult to treat. Identification of patients at low risk for repeat revascularization may allow clinicians to reserve stents for patients most likely to benefit.

METHODS

Data from five interventional trials (5,146 patients) were pooled for analysis. We identified patients with optimal angiographic results (final diameter stenosis < or =30% and no dissection) after balloon angioplasty and determined the multivariable predictors of repeat revascularization.

RESULTS

Optimal angiographic results were achieved in 18% of patients after angioplasty. The repeat revascularization rate at six months was lower for patients with optimal results (20% vs. 26%, p < 0.001) but still higher than observed in stent trials. Independent predictors of repeat revascularization were female gender (odds ratio [OR] 1.67, p = 0.01), lesion length > or =10 mm (OR 1.62, p = 0.03) and proximal left anterior descending coronary artery lesions (OR 1.62, p = 0.03). For the 8% of patients with optimal angiographic results and none of these risk factors, the repeat revascularization and target vessel revascularization rates were 14% and 8% respectively, similar to rates after stent implantation. Cost analysis estimated that $78 million per year might be saved in the U.S. with a provisional stenting strategy using these criteria compared with elective stenting.

CONCLUSIONS

A combination of baseline characteristics and angiographic results can be used to identify a small group of patients at very low risk for repeat revascularization after balloon angioplasty. Provisional stenting for these low risk patients could substantially reduce costs without compromising clinical outcomes.

Comparison of outcomes of coronary stenting versus conventional coronary angioplasty in the department of veterans affairs medical centers

Although the short-term benefits of stent deployment have been established, less is known about long-term outcomes. This study compares short- and long-term outcomes in veterans undergoing stenting and conventional coronary angioplasty. We used Department of Veterans Affairs databases to identify 27,224 veterans who had undergone percutaneous coronary intervention (PCI) in Veterans Affairs medical centers between October 1994 and September 1999. Patients were classified according to whether they had acute myocardial infarction (AMI) as the principal diagnosis. Baseline characteristics were similar in the stent and conventional groups. In AMI, hospital mortality was 2.9% for those with stents and 4.8% for those who underwent conventional coronary angioplasty (p <0.0001), whereas for patients without AMI, hospital mortality was similar (1.2% vs 1.4%, p = 0.12). For AMI, same-admission bypass surgery rates were lower in the stent group (0.7% vs 3.2%, p <0.0001) and in the group without AMI (1.2% vs 3.3%, p <0.0001). Two-year survival was better for stenting in veterans with (90% vs 88%, p = 0.006) and without (92% vs 91%, p = 0.008) AMI. For AMI, 2-year rehospitalization rates for PCI (10% vs 13%, p <0.0001), coronary artery bypass surgery (4% vs 6%, p <0.0001), and unstable angina (17% vs 23%) were lower for those who had stenting. In the no-AMI group, 2-year rehospitalization rates for PCI (14% vs 17%, p <0.0001), coronary artery bypass surgery (5% vs 8%, p <0.0001), and unstable angina (22% vs 29%, p <0.0001) were lower in the stent group. Veterans who underwent stenting had lower hospital mortality, reduced rates of same-admission bypass surgery, marginally better survival, and lower rates of rehospitalization than their counterparts who had conventional coronary angioplasty.

Ultrasound guidance: technique and results of aggressive ultrasound-guided PTCA. The UPSIZE Pilot Trial

Stenting results in a larger lumen than conventional balloon angioplasty. This is the major determinant of a good acute and long-term result. In this non-randomised, single centre trial, intravascular ultrasound was used preinterventionally to guide the choice of the balloon size. The aim was to achieve a maximum lumen area with balloon angioplasty only. We included 346 patients with 360 lesions. The diameter of the external elastic lamina by intravascular ultrasound was 4.67 mm. A mean balloon size of 4.0 mm was chosen. The initial luminal gain was 1.82 mm, the lumen area post intervention was 6.6 mm(2). Dissections occurred frequently but the incidence of major adverse events was not increased. At one year follow-up, the overall event free survival was 81%. Target lesion revascularisation was performed in 34 patients (10%). An angiographic follow-up was available for 261 patients (76%). Restenosis (> 50% diameter Stenosis) was found in 21%. The results show, that ultrasound guidance of balloon angioplasty provides a means to achieve a large initial luminal gain without the routine use of stents. The acute and long-term results suggest that the approach is safe and efficient. The data compare favorably with similar studies using advanced intravascular diagnostic tools to guide the angioplasty procedure.

Trials comparing coronary artery bypass grafting with percutaneous transluminal coronary angioplasty and primary stent implantation in patients with multivessel coronary artery disease

With marked improvements in stent technology as adjunct to balloon angioplasty for multivessel coronary disease, several newer trials are currently in progress reviewing the optimal revascularization strategy. This review provides background from older studies and addresses the current progress and design of these newer trials.

Provisional stenting strategies: systematic overview and implications for clinical decision-making

Coronary stents reduce the rates of abrupt closure, emergency coronary artery bypass graft surgery and restenosis, but do not prevent myocardial infarction or death at six months. The financial burden of increased stent use and the difficulty in managing in-stent restenosis have provided the impetus to develop provisional stenting strategies. Patients at low risk for restenosis after balloon angioplasty may not derive additional benefit from stent implantation and may be successfully managed with percutaneous transluminal coronary angioplasty (PTCA) alone. Numerous patient, lesion and procedural predictors of restenosis have been identified. Postprocedural assessment using quantitative coronary angiography, intravascular ultrasound (IVUS), coronary flow velocity reserve (CVR) or fractional flow reserve (FFR) may further enhance the ability to predict adverse outcomes after PTCA. Several studies have been performed to investigate the feasibility of provisional stenting strategies using various modalities to identify low risk patients who could be managed with PTCA alone. An optimal or "stent-like" angiographic result after PTCA is associated with favorable clinical outcomes. Preliminary results of studies using IVUS or CVR to guide provisional stenting appear promising. Angiography alone may be inadequate to identify truly low risk patients and may need to be combined with clinical factors, assessment of recoil, IVUS or physiologic indexes. Strategies that avoid unnecessary stenting in even a small proportion of patients may have large impacts on health care costs. Provisional stenting may potentially reduce costs and rates of in-stent restenosis without compromising the quality of health care delivery.

Clopidogrel: a review of its use in the prevention of atherothrombosis

Clopidogrel is an ADP receptor antagonist that is indicated for the reduction of atherosclerotic events including myocardial infarction, ischaemic stroke and vascular death in patients with atherosclerosis manifested by recent stroke, myocardial infarction or established peripheral vascular disease. In the 19 185 patients enrolled in the multicentre, randomised double-blind CAPRIE study, the annual risk of the combined end-point of ischaemic stroke, myocardial infarction and death from vascular disease (vascular death) was significantly lower during treatment with clopidogrel 75 mg/day than aspirin 325 mg/day [5.3 vs 5.8%/year, respectively; relative risk reduction (RRR) 8.7%, p = 0.043] after a mean follow-up of 1.9 years. Clopidogrel provided even greater reductions in the risk of recurrent ischaemic events than aspirin in patients with a history of coronary artery bypass surgery, diabetes mellitus and in those receiving concomitant lipid-lowering therapy. Moreover there was a significant reduction in the incidence of hospitalisation in patients treated with clopidogrel. In a patient population (Saskatchewan, Canada) with a greater risk of ischaemic events than the CAPRIE study population, the number of patients needed to be treated with clopidogrel to prevent 1 ischaemic event was estimated to be 70 (vs 200 in the CAPRIE study). In randomised trials and registry surveys, clopidogrel 75 mg/day plus aspirin had similar efficacy (as measured by adverse cardiac outcomes) to ticlopidine 250mg twice daily plus aspirin during the 30 days after placement of intracoronary stents. Tolerability of clopidogrel was significantly better than ticlopidine in the randomised, double-blind CLASSICS study. Among patients treated with clopidogrel or aspirin in the CAPRIE study, the overall gastrointestinal tolerability of clopidogrel was generally better than that of aspirin; the frequency of gastrointestinal haemorrhage was significantly lower among patients treated with clopidogrel than aspirin. Diarrhoea, rash and pruritus were significantly more common with clopidogrel than aspirin.

CONCLUSION

Clopidogrel was significantly more effective than aspirin in the prevention of vascular events (ischaemic stroke, myocardial infarction or vascular death) [corrected] in patients with atherothrombotic disease manifested by recent myocardial infarction, recent ischaemic stroke or symptomatic peripheral arterial occlusive disease [corrected] in the CAPRIE study. The overall tolerability profile of the drug was similar to that of aspirin, although gastrointestinal haemorrhage occurred significantly less often in clopidogrel recipients. The drug is widely used in combination with aspirin for the prevention of atherothrombosis after placement of intravascular stents, and available data suggest that this combination is as effective as ticlopidine plus aspirin for this indication.