Detailed angiographic analysis of high-speed mechanical rotational atherectomy in human coronary arteries

A Cardiac-Targeted Nanozyme Interrupts the Inflammation-Free Radical Cycle in Myocardial Infarction

Severe systemic inflammation following myocardial infarction (MI) is a major cause of patient mortality. MI-induced inflammation can trigger the production of free radicals, which in turn ultimately leads to increased inflammation in cardiac lesions (i.e., inflammation-free radicals cycle), resulting in heart failure and patient death. However, currently available anti-inflammatory drugs have limited efficacy due to their weak anti-inflammatory effect and poor accumulation at the cardiac site. Herein, a novel Fe-Cur@TA nanozyme is developed for targeted therapy of MI, which is generated by coordinating Fe3+ and anti-inflammatory drug curcumin (Cur) with further modification of tannic acid (TA). Such Fe-Cur@TA nanozyme exhibits excellent free radicals scavenging and anti-inflammatory properties by reducing immune cell infiltration, promoting macrophage polarization toward the M2-like phenotype, suppressing inflammatory cytokine secretion, and blocking the inflammatory free radicals cycle. Furthermore, due to the high affinity of TA for cardiac tissue, Fe-Cur@TA shows an almost tenfold greater in cardiac retention and uptake than Fe-Cur. In mouse and preclinical beagle dog MI models, Fe-Cur@TA nanozyme preserves cardiac function and reduces scar size, suggesting promising potential for clinical translation in cardiovascular disease.

Predictors of no- reflow during primary angioplasty for acute myocardial infarction, from Medical College Hospital, Trivandrum

Background

Primary angioplasty (PCI) for acute myocardial infarction is associated with no-reflow phenomenon, in about 5–25% of cases. Here we analysed the factors predicting no reflow .

Methods

This was a case control study of consecutive patients with acute myocardial infarction who underwent Primary PCI from August 2014 to February 2015.

Results

Of 181 patients who underwent primary PCI, 47 (25.9%) showed an angiographic no-reflow phenomenon. The mean age was 59.19 ± 10.25 years and females were 11%.

Univariate predictors of no reflow were age >60 years (OR = 6.146, 95%CI 2.937–12.86, P = 0<0.001), reperfusion time >6 h (OR = 21.94, 95%CI 9.402–51.2, P = < 0.001), low initial TIMI flow (≤1) (OR = 12.12, 95%CI 4.117–35.65, P < 0.001), low initial TMPG flow (≤1) (OR = 36.19, 95%CI 4.847–270.2, P < 0.001) a high thrombus burden (OR = 11.04,95%CI 5.124–23.8, P < 0.001), a long target lesion (OR = 8.54, 95%CI 3.794–19.23, P < 0.001), Killip Class III/IV(OR = 2.937,95%CI 1.112–7.756,P = 0.025) and overlap stenting(OR = 3.733,95%CI 1.186–11.75,P = 0.017).

Multiple stepwise logistic regression analysis predictors were: longer reperfusion time > 6 h (OR = 13.844, 95%CI 3.214–59.636, P = <0.001), age >60 years (OR = 8.886, 95%CI 2.145–36.80, P = 0.003), a long target lesion (OR = 8.637, 95%CI 1.975–37.768, P = 0.004), low initial TIMI flow (≤1) (OR = 20.861, 95%CI 1.739–250.290, P = 0.017).

Conclusions

It is important to minimize trauma to the vessel, avoid repetitive balloon dilatations use direct stenting and use the shortest stent if possible.

Coronary Atherectomy in the United States (from a Nationwide Inpatient Sample)

Contemporary real-world data on clinical outcomes after utilization of coronary atherectomy are sparse. The study cohort was derived from Healthcare Cost and Utilization Project Nationwide Inpatient Sample database from year 2012. Percutaneous coronary interventions including atherectomy were identified using appropriate International Classification of Diseases, 9th Revision diagnostic and procedural codes. Two-level hierarchical multivariate mixed models were created. The primary outcome was a composite of in-hospital mortality and periprocedural complications; the secondary outcome was in-hospital mortality. Hospitalization costs were also assessed. A total of 107,131 procedures were identified in 2012. Multivariate analysis revealed that atherectomy utilization was independently predictive of greater primary composite outcome of in-hospital mortality and complications (odds ratio 1.34, 95% confidence interval 1.22 to 1.47, p <0.001) but was not associated with any significant difference in terms of in-hospital mortality alone (odds ratio 1.22, 95% confidence interval 0.99 to 1.52, p 0.063). In the propensity-matched cohort, atherectomy utilization was again associated with a higher rate of complications (12.88% vs 10.99%, p = 0.001), in-hospital mortality +a ny complication (13.69% vs 11.91%, p = 0.003) with a nonsignificant difference in terms of in-hospital mortality alone (3.45% vs 2.88%, p = 0.063) and higher hospitalization costs ($25,341 ± 353 vs $21,984 ± 87, p <0.001). Atherectomy utilization during percutaneous coronary intervention is associated with a higher rate of postprocedural complications without any significant impact on in-hospital mortality.

Rotational atherectomy: Technical update

Percutaneous coronary intervention is currently the most common form of revascularization for symptomatic coronary artery disease. In elderly, diabetic and renal patients, there is an increased prevalence of calcified coronary disease. Rotational atherectomy (RA) can be useful in the treatment of these lesions. Plaque removal was initially proposed as an alternative to balloon angioplasty, hence RA required high-velocity protocols with large-sized burrs (over 2.0 mm). With a high incidence of acute complications and disappointing restenosis rates, the use of RA dwindled. However, the advent of drug-eluting stents, which significantly decreased the rate of restenosis, led to the repositioning of RA as an adjunctive technique in the preparation of densely calcified lesions, improving stent delivery and expansion. In recent years, a better understanding of the mechanism of action of RA has changed it from a plaque debulking to a compliance modifying technique. As a result, RA has become less aggressive, using smaller size burrs and lower rotational speeds. This conservative approach has improved immediate results, with increased safety and better long-term outcomes. In this review paper, the technique of RA is explained in the light of current knowledge.

Rotational atherectomy: a "survivor" in the drug-eluting stent era

Mechanical debulking of coronary plaques with rotational atherectomy (RA) has been used for more than 20 years during percutaneous coronary interventions (PCI). Modification of plaque characteristics may be accomplished with selective ablation of inelastic fibrocalcific tissue. The use of RA, though reduced with the development of bare-metal stents (BMS) and even more with drug-eluting stents (DES), has never been completely abandoned. The present review will analyze reasons for conflicting results obtained in large series and randomized trials on this topic in the past, and will identify criteria for an appropriate use in current times.

Management of the no-reflow phenomenon

The lack of reperfusion of myocardium after prolonged ischaemia that may occur despite opening of the infarct-related artery is termed "no reflow". No reflow or slow flow occurs in 3-4% of all percutaneous coronary interventions, and is most common after emergency revascularization for acute myocardial infarction. In this setting no reflow is reported to occur in 30% to 40% of interventions when defined by myocardial perfusion techniques such as myocardial contrast echocardiography. No reflow is clinically important as it is independently associated with increased occurrence of malignant arrhythmias, cardiac failure, as well as in-hospital and long-term mortality. Previously the no-reflow phenomenon has been difficult to treat effectively, but recent advances in the understanding of the pathophysiology of no reflow have led to several novel treatment strategies. These include prophylactic use of vasodilator therapies, mechanical devices, ischaemic postconditioning and potent platelet inhibitors. As no reflow is a multifactorial process, a combination of these treatments is more likely to be effective than any of these alone. In this review we discuss the pathophysiology of no reflow and present the numerous recent advances in therapy for this important clinical problem.

Increase in serum troponin-I following rotational atherectomy reliably predicts the occurrence of reversible wall motion abnormalities

BACKGROUND

There is growing evidence that microdebris pulverized by rotational atherectomy (RA) may have a deleterious effect on coronary microcirculation and ventricular contraction. However, the incidence and the predictors of worsening of left ventricular wall motion following RA are unknown.

METHODS

Thirty patients without a known previous anterior wall myocardial infarction who underwent RA-facilitated angioplasty for de novo lesions of left anterior descending coronary artery were evaluated. Global and anterior wall regional left ventricular ejection fraction (LVEF and AREF) were analyzed before and after RA. Serum troponin-I, CK, and CK-MB concentrations were assayed.

RESULTS

Target lesion length was greater (P=0.03), post-procedural minimal lumen diameter was smaller (P<0.01), and serum troponin-I immediately after RA was higher (P=0.01) in 16 patients with a decrease in the AREF of at least 15% than in those without. Stepwise logistic regression analysis identified one independent predictor of such worsening of AREF, troponin-I> or =0.1 ng/ml immediately after the procedure (P<0.01), with sensitivity of 81%, specificity of 79%, and relative risk of 3.8.

CONCLUSIONS

Our results suggest that RA can cause substantial deterioration in left ventricular wall motion. Serum troponin-I, a sensitive indicator of myocardial damage, may be useful in predicting reversible LV wall motion abnormalities following RA.

Impact of Platelet Glycoprotein IIb/IIIa Inhibitor Therapy on In-Hospital Outcomes and Long-Term Survival Following Percutaneous Coronary Rotational Atherectomy

BACKGROUND

Percutaneous coronary rotational atherectomy (PCRA) is a potent stimulus of platelet activation and aggregation in vivo. For this reason, many patients undergoing PCRA are treated with platelet glycoprotein (GP) IIb/IIIa inhibitors. However, there is limited data regarding the ability of GP IIb/IIIa inhibitors to reduce ischemic complications of PCRA and no data regarding their effect on long-term survival.

METHODS

Data on 1138 consecutive patients undergoing PCRA in 5 hospitals in 1998-1999 were pooled and analyzed. Long-term survival was available for all 530 patients treated in 3 of the hospitals.

RESULTS AND CONCLUSIONS

GP IIb/IIIa inhibitors were administered to 315 of 1138 (28%) PCRA patients. There was no difference in age, gender or race among patients treated with and without GP IIb/IIIa antagonists. The prevalence of hypertension, diabetes, renal insufficiency and peripheral vascular disease did not differ between groups. Unstable angina was more common among patients treated with GP IIb/IIIa inhibitors (45% vs. 38%, P = 0.036) Patients treated with GP IIb/IIIa inhibitors had lower ejection fractions (50% vs. 55%, P < 0.001) and more 3-vessel coronary disease (24% vs. 16%, P = 0.002). Angiographic success was over 99% in both groups (P = NS). The frequency of major adverse cardiovascular events (MACE) was slightly greater in GP IIb/IIIa inhibitor treated patients (3.8% vs. 2.2%, P = 0.126). At a mean follow-up of 3 years, mortality was 13.3% in the GP IIb/IIIa treated patients and 12% in the untreated patients (P = 0.224). On Cox proportional hazards analysis, treatment with a GP IIb/IIIa inhibitor was not significantly associated with increased survival (Hazard Ratio, 0.81, 95% Confidence Interval, 0.631-1.039, P = 0.098). These data do not indicate a significant association between GP IIb/IIIa inhibitor treatment during PCRA and MACE or survival.

CONDENSED ABSTRACT

There is limited data regarding the ability of GP IIb/IIIa inhibitors to reduce ischemic complications of percutaneous coronary rotational atherectomy (PCRA) and no data regarding their effect on long-term survival. These data do not indicate a significant association between GP IIb/IIIa inhibitor treatment during PCRA and MACE or survival.

High-speed rotational atherectomy and coronary stenting: QCA and QCU analysis

To evaluate the acute effect of pretreatment with high-speed rotational atherectomy (HSRA) on stent deployment (rotastenting), we studied 33 patients with rotastenting of 40 segments, 34 patients with 40 coronary segments treated with Palmaz-Schatz stenting alone, and 34 patients with 40 segments treated with HSRA. The HSRA- and stent-alone patient groups were selected retrospectively by matching the quantitative coronary angiography (QCA) reference diameter (D ref). QCA revealed similar baseline percent of stenosis (85.3% +/- 12.4%), minimal luminal diameter (MLD), and D ref. The percent area expansion was calculated as a ratio between the minimal intrastent area and the reference area measured by intracoronary ultrasound. The rotastent group was characterized by more frequent calcification compared to HSRA and stent groups (67.5% vs. 20% and 12.5%; P < 0.01). Lesion length determined by QCA was longer both in the HSRA and the rotastent groups vs. the stent-alone group (21.1 +/- 12.3 and 20.9 +/- 4.3 vs. 17.0 +/- 7.7 mm; P < 0.05). In this small study, there was no difference demonstrated between final MLD in the rotastent and stent-alone groups. However, a smaller MLD was achieved in the HSRA group (3.0 +/- 0.7 vs. 3.1 +/- 0.5 vs. 2.5 +/- 0.7 mm, respectively; P < 0.01). The degree of stent expansion was higher in the rotastent group compared to the stent-alone group (91.9% +/- 4.4% vs. 79.7% +/- 3.4%; P < 0.03) and the % residual area of plaque was less for the rotastent group than for the stent-alone group (12.1% +/- 13.2% vs. 21.1% +/- 17.5%; P = 0.03). These data suggest that antecedent HSRA atheroma debulking using HSRA results in improved intravascular stent expansion and reduction in residual plaque, facilitating optimal stent deployment.

Clinical outcome of percutaneous transluminal coronary rotational atherectomy in patients with end-stage renal disease

The clinical results of percutaneous transluminal coronary rotational atherectomy (PTCRA) in dialysis patients were retrospectively evaluated in comparison with coronary artery bypass grafting (CABG). From 1997 to 2001, 44 consecutive dialysis patients with 61 lesions underwent PTCRA and 55 consecutive dialysis patients underwent CABG. The initial success rate of PTCRA was 98%. The PTCRA group had a shorter hospital stay (13+/-17 vs 60+/-35 days, p=0.0001) and a lower rate of complications (11% vs 42%, p=0.001) than the CABG group. Although neither event-free survival without death nor myocardial infarction (MI) was significantly different between the CABG and PTCRA groups during the mean follow-up period of 21+/-14 months, 20 patients (45%) in the PTCRA group needed repeat revascularization of the target lesion. In conclusion, PTCRA may be a safe alternative modality for revascularization of high-risk CABG candidates, with excellent short-term results although the long-term outcome is inferior to that of CABG because of the higher restenosis rate.

Comparison of rotational atherectomy with conventional balloon angioplasty in the prevention of restenosis of small coronary arteries: results of the Dilatation vs Ablation Revascularization Trial Targeting Restenosis (DART)

BACKGROUND

The optimum treatment of obstructive coronary disease in small (<3.0 mm diameter) arteries remains unknown. Rotational atherectomy is an approved treatment that might reduce the vascular injury during percutaneous coronary intervention compared with angioplasty. We report on a multicenter, randomized, blinded end point trial comparing rotational atherectomy with balloon angioplasty in the prevention of restenosis of obstructed small coronary arteries.

METHODS

A total of 446 patients with myocardial ischemia associated with an angiographic stenosis in a native coronary artery 2 to 3 mm in diameter and < or =20 mm in length without severe calcification were randomly assigned to receive rotational atherectomy (n = 227) or balloon angioplasty (n = 219). The primary end point was target vessel failure at 12 months (defined as the composite of death, Q-wave myocardial infarction, and clinically driven repeat revascularization of the target vessel).

RESULTS

The mean reference vessel diameter was 2.46 +/- 0.40 mm, the mean lesion length was 9.97 +/- 5.59 mm, and the prevalence of diabetes mellitus was 32%. Acute procedural success (91.6% for rotational atherectomy, 94.1% for balloon angioplasty, P =.36) and target vessel failure at 12 months were not significantly different (30.5% vs 31.2%, P =.98). At 8 months, there were no significant differences in minimum lumen diameter (1.28 +/- 0.63 mm vs 1.19 +/- 0.54 mm, P =.26), percent diameter stenosis (28% +/- 12% vs 29% +/- 15%, P =.59), binary restenosis rate (50.5% vs 50.5%, P = 1.0), or late loss index (0.57 vs 0.62, P =.7). No Q-wave myocardial infarctions occurred in either arm of the study, and non-Q-wave myocardial infarctions (defined as creatine kinase level >2 times normal with an elevated creatine kinase-myocardial band isoenzyme level) occurred in 2.2% and 1.4% of the patients in the rotational atherectomy and balloon angioplasty groups, respectively (P =.72).

CONCLUSION

Rotational atherectomy was found to be safe in the treatment of obstructed small arteries, but lower rates of target vessel failure were not achieved compared with balloon angioplasty. Because the acute gain and loss index ratios of the 2 treatments were similar, there was no evident beneficial antirestenosis mechanism seen for rotational atherectomy.

Prolongation of QT interval as a predictor of no-reflow induced by rotational atherectomy

Although coronary rotational atherectomy (RA) is widely applied to clinical cases, the incidence of coronary no-reflow associated with it is higher than in percutaneous transluminal coronary angioplasty (PTCA) and stenting. This study was undertaken to predict no-reflow by using conventional electrocardiograms (ECGs). A total of 105 patients who underwent RA (group 1) and 40 who underwent PTCA (group 2) were studied. Eight patients of group 1, all of whom had long calcified coronary lesions, were complicated with no-reflow following RA. Standard 12-lead ECGs were recorded before and throughout the interventional procedures. Maximum and minimum QT intervals and QT dispersion were measured and corrected by heart rate. Corrected and uncorrected QT intervals and QT dispersion were significantly prolonged by RA in group 1 patients without no-reflow: maximum QTc, 428 +/- 28 ms --> 485 +/- 53 ms, p<0.001. The increases in QT intervals were more remarkable in group 1 patients with no-reflow: maximum QTc, 434 +/- 15 ms --> 552 +/- 39 ms, p<0.001. Of the 33 patients with maximum QTc > or = 500 ms, 8 were complicated with no-reflow. No patients with maximum QTc < 500 ms had no-reflow. There was no significant increase in QT intervals in group 2. Adsorption of calcium ions from the myocardium by pulverized calcified atheromatous debris when these pass through coronary capillaries, resulting in transient myocardial hypocalcemia, was considered as a possible mechanism of QT prolongation. Because QT prolongation appears during the initial RA trial, prolonged QT intervals could be a predictor of no-reflow. It is recommended to avoid repetitive RA if marked QT prolongation is observed at the initial RA trial.

Long-term clinical outcome and predictors of major adverse cardiac events after percutaneous interventions on saphenous vein grafts

OBJECTIVES

The purpose of this study was to examine the long-term clinical outcome after percutaneous intervention of saphenous vein grafts (SVG) and to identify the predictors of major adverse cardiac events (MACE).

BACKGROUND

Percutaneous interventions of SVGs have been associated with more procedural complications and higher restenosis rates compared with interventions on native vessels.

METHODS

From 1993 to 1997, 1,062 patients underwent percutaneous intervention on 1,142 SVG lesions. Procedural, in-hospital and long-term clinical outcomes were recorded in a database and analyzed.

RESULTS

In-hospital MACE occurred in 137 patients (13%) including death (8%), Q-wave myocardial infarction (MI) (2%) and coronary artery bypass surgery (3%). Late MACE occurred in 565 patients (54%) including death (9%), Q-wave MI (9%) and target vessel revascularization (36%). Any MACE occurred in 457 (43%) patients. Follow-up was available in 1,056 (99%) patients at 3 +/- 1 year. Univariate predictors were restenotic lesion (odds ratio [OR]: 2.47, confidence interval [CI]: 1.13 to 3.85, p = 0.0003), unstable angina (OR: 1.99, CI: 1.27 to 2.91, p = 0.04) and congestive heart failure (CHF) (OR: 1.97, CI: 1.14 to 3.24, p = 0.02) for in-hospital MACE, and peripheral vascular disease (PVD) (OR: 2.18, CI: 1.34 to 3.44, p = 0.002), intra-aortic balloon pump placement (OR: 2.08, CI: 1.13 to 3.85, p = 0.02) and previous MI (OR: 1.97, CI: 1.14 to 3.25, p = 0.007) for late MACE. Independent multivariate predictors for late MACE were restenotic lesion (relative risk [RR] 1.33, p = 0.02), PVD (RR: 1.31, p = 0.01), CHF (RR: 1.42, p = 0.01) and multiple stents (RR: 1.47, p = 0.004). Angiographic follow-up was available for 422 patients. Angiographic restenosis occurred in 122 (29%) of stented SVGs and 181 (43%) of nonstented SVGs (p = 0.04). Stent implantation did not confer a survival benefit.

CONCLUSIONS

Despite the use of new interventional devices, SVG interventions are associated with significant morbidity and mortality; SVG stenting is not associated with better three-year event-free survival. This may be due to progressive disease at nonstented sites.

Angiographic analysis of immediate and long-term results of PTCR vs. PTCA in complex lesions (COBRA study)

We conducted a prospective, randomized trial to compare immediate and long-term effects of percutaneous transluminal coronary angioplasty (PTCA) and high-frequency rotational atherectomy (PTCR) in patients with angiographically predefined complex coronary artery lesions (AHA type B2 and C). The relation of lesion characteristics to procedural results is reported in this angiographic analysis. Patients were randomly assigned to balloon angioplasty (n = 250 patients) or rotational atherectomy (n = 252 patients). Quantitative coronary angiography could be performed in 447 patients to evaluate immediate results and in 293 patients with a 6-month angiographic follow-up. Procedural success was comparable in the PTCR and in the PTCA group (80% vs. 76%, P = 0.260). The need for stent implantation due to a residual stenosis >50% or a bail-out situation was significantly higher in the PTCA group (9.7% vs. 2.0%, P = 0.001). In both treatment groups, diameter stenosis was effectively reduced and MLD increased. The acute gain did not differ between the two groups. At 6-month control, the restenosis rate was comparable in the PTCR and in the PTCA group (37% vs. 35%, P = 0.658), whereas diameter stenosis was significantly more severe in the PTCR group than in the PTCA group (52% vs. 46%, P = 0.039) and, correspondingly, the MLD was significantly smaller in the PTCR group (1.29 mm vs. 1.44 mm, P = 0.031). Late loss was about the same in both groups, however, net gain and net gain index were significantly higher in the PTCA group (0.82 mm vs. 0.64 mm, P = 0.008; and 31% vs. 24%, P = 0.009). Analysis of procedural results for various lesion characteristics revealed no significant difference between treatment groups. In this randomized trial, complex coronary artery lesions were treated with comparable results for angiographic and procedural success and the restenosis rate by both, PTCA and PTCR. Late loss, however, was significantly higher and net gain significantly smaller after PTCR. Stents, although infrequently used, had a relevant impact on immediate PTCA results but not on late results. Cathet Cardiovasc Intervent 2001;53:359-367.

Coronary angioplasty and Rotablator atherectomy trial (CARAT): immediate and late results of a prospective multicenter randomized trial

Mechanical rotational atherectomy with the Rotablator is widely used for percutaneous coronary revascularization, but the ideal debulking strategy remains unknown. The purpose of this study was to compare the immediate and late results after Rotablator using two treatment strategies: Large burrs (burr/artery ratio of >0.7) to achieve maximal debulking (lesion debulking strategy) or small burrs (burr/artery ratio < or = 0.7) to modify lesion compliance (lesion modification strategy). Two hundred twenty-two patients at six centers were prospectively enrolled in this study and randomly assigned to large (n = 104 patients with 118 lesions) or small (n = 118 patients with 136 lesions) burrs. The primary endpoint was final diameter stenosis at the end of the procedure, and secondary endpoints included inhospital angiographic and clinical complications, and target lesion revascularization at 6 months. Baseline demographic and angiographic characteristics were similar. There were no differences in procedural success, the extent of immediate lumen enlargement, inhospital ischemic complications, or late target vessel revascularization. However, compared with small burrs, patients randomized to large burrs were more likely to experience serious angiographic complications (5.1% vs. 12.7%, P < 0.05) immediately after atherectomy. This study suggests that a routine lesion modification strategy employing small burrs (burr/artery ratio < or = 0.7) achieves similar immediate lumen enlargement and late target vessel revascularization compared with a more aggressive debulking strategy (burr/artery ratio >0.7), but with fewer angiographic complications.

[In-hospital major complications associated with rotational atherectomy: experience with 800 patients at a single center]

INTRODUCTION

Rotational atherectomy is usually performed in patients with angiographically determined high risk coronary lesions. The aim of this study was to evaluate the rate of major adverse cardiac events (death, Q-wave infarction or new revascularization) after rotational atherectomy, as well as to identify the clinical characteristics associated with this incidence.

PATIENTS AND METHODS

The study population included 800 patients treated with rotational atherectomy from 1993 to 1999: 512 (64%), for de novo lesions, and 288 (36%) for restenosis. Balloon dilation and coronary stenting was performed in 95% and 34% of patients, respectively.

RESULTS

During hospitalization, 17 patients (2.1%) died, 16 (2%) had a Q-wave infarction, 30 (3.8%) a non-Q infarction, and new revascularization was performed in 28 (3.5%). The incidence of major adverse cardiac events was 6.5% (n = 52), this incidence being higher in the presence of diabetes (8.9 vs. 4.4%; p = 0.01), unstable angina or acute/recent myocardial infarction (7.6 vs. 3.3%; p = 0.02), multivessel disease (8.6 vs. 3.3%; p < 0.01), treated vessel other than right coronary (7.0 vs. 1.7%; p = 0.01), procedure in > 1 vessel (10.7 vs. 4.7%; p < 0.01), angiographic failure (62.5 vs. 5.5%; p < 0.001), and de novo lesions (8.4 vs. 2.5%; p < 0.01), with diabetes and treatment of de novo lesions being independent predictors of major adverse cardiac events. However, age, previous infarction, and left ventricular dysfunction, were not associated with the rate of events.

CONCLUSION

Some simple variables are associated with a higher incidence of major adverse cardiac events after rotational atherectomy. Advanced age, previous infarction and left ventricular dysfunction, however, do not necessarily imply a poorer prognosis in these patients.

Side-branch occlusion after rotational atherectomy of in-stent restenosis: incidence, predictors, and clinical significance

We evaluated the incidence, predictors, and clinical significance of side-branch occlusion (SBO) after rotational atherectomy (RA) for treatment of in-stent restenosis (ISR) and compared it with those of native coronary artery (NC). RA was performed in 64 patients with 34 ISR (42 side branches) and 30 NC (40 side branches). SBO occurred 14% after RA in ISR group compared with 0% in NC group (P < 0.05), and 33% after adjunctive balloon inflation in ISR group compared with 2.5% in NC group (P < 0.01). Non-Q myocardial infarction developed in seven patients in ISR group and four patients in NC group (P = NS). The presence of significant side-branch (SB) ostial disease (OR = 4.7, P < 0.05) and ISR lesions (OR = 15.5, P < 0.05) were the only independent predictors of SBO by multivariate analysis. The incidence of SBO is higher after RA of ISR than RA of NC and may be associated with an increased risk of non-Q myocardial infarction.

Coronary microembolization--its role in acute coronary syndromes and interventions

The diagnosis coronary artery disease is classically based on patient's symptoms and morphology, as analyzed by angiography. The importance of risk factors for the development of coronary atherosclerosis and disturbance of coronary vasomotion is clearly established. However, microembolization of the coronary circulation has also to be taken into account. Microembolization may occur as a single or as multiple, repetitive events, and it may induce inflammatory responses. Spontaneous microembolization may occur, when the fibrous cap of an atheroma or fibroatheroma (Stary i.v. and Va) ruptures and the lipid pool with or without additional thrombus formation is washed out of the atheroma into the microcirculation. Such events with progressive thrombus formation are known as cyclic flow variations. Plaque rupture occurs more frequently than previously assumed, i.e. in 9% of patients without known heart disease suffering a traffic accident and in 22% of patients with hypertension and diabetes. Also, in patients dying from sudden death microembolization is frequently found. Patients with stable and unstable angina show not only signs of coronary plaque rupture and thrombus formation, but also microemboli and microinfarcts, the only difference between those with stable and unstable angina being the number of events. Appreciation of microembolization may help to better understand the pathogenesis of ischemic cardiomyopathy, diabetic cardiomyopathy and acute coronary syndromes, in particular in patients with normal coronary angiograms, but plaque rupture detected by intravascular ultrasound. Also, the benefit from glycoprotein IIb/IIIa receptor antagonist is better understood, when not only the prevention of thrombus formation in the epicardial atherosclerotic plaque, but also that of microemboli is taken into account. Microembolization also occurs during PTCA, inducing elevations of troponin T and I and elevations of the ST segment in the EKG. Elevated baseline coronary blood flow velocity, as a potential consequence of reactive hyperemia in myocardium surrounding areas of microembolization, is more frequent in patients with high frequency rotablation than in patients with stenting and in patients with PTCA. The hypothesis of iafrogenic microembolization during coronary interventions is now supported by the use of aspiration and filtration devices, where particles with a size of up to 700 microns have been retrieved. In the experiment, microembolization is characterized by perfusion-contraction mismatch, as the proportionate reduction of flow and function seen with an epicardial stenosis is lost and replaced by contractile dysfunction in the absence of reduced flow. The analysis of the coronary microcirculation, in addition to that of the morphology and function of epicardial coronary arteries, and in particular appreciation of the concept of microembolization will further improve the understanding of the pathophysiology and clinical symptoms of coronary artery disease.

Lower restenosis rate with stenting following aggressive versus less aggressive rotational atherectomy

The present study evaluated the acute and follow-up results of stenting following aggressive rotational atherectomy compared with stenting following less aggressive rotational atherectomy. Recent work has demonstrated that stenting following rotational atherectomy is a promising strategy for complex and calcified lesions. However, there is little information available regarding the optimal procedural technique of rotational atherectomy to be employed before stent implantation. Between May 1995 and February 1997, 162 lesions in 126 patients were stented following rotational atherectomy because of the presence of severe calcification on fluoroscopy or intravascular ultrasound (95%). The lesions were divided as to whether aggressive rotational atherectomy was performed or not. Aggressive rotational atherectomy, defined as the use of a final burr size > or =2.25 mm and/or final burr/vessel ratio > or =0.8, was performed in 56 lesions. A less aggressive rotational atherectomy strategy was performed in 106 lesions. Procedural Q-wave (8.9% vs. 1.9%, P<0.05) and non-Q-wave (11% vs. 1.9%, P<0.05) myocardial infarctions were observed more frequently after aggressive rotational atherectomy; there was no significant difference in the incidence of other procedural complications. Although there was no significant difference in minimal lumen diameter after the procedure (3.11+/-0.68 vs. 2.99+/-0.48 mm, NS), at follow-up a greater minimal lumen diameter was observed in the lesions treated with aggressive rotational atherectomy compared to those treated with less aggressive rotational atherectomy (2.12+/-1.31 vs. 1.56+/-0.89 mm, P<0.01). Restenosis rates were 50.0% in the lesions treated without aggressive rotational atherectomy and 30.9% in those treated with aggressive rotational atherectomy (P<0.05). There was no significant difference in the incidence of restenosis with a focal pattern between the two groups (25.0% vs. 21.4%, NS). In contrast, restenosis with a diffuse pattern was lower in lesions treated with aggressive rotational atherectomy than in those without aggressive rotational atherectomy (9.5% vs. 25.0%, P<0.05). Aggressive rotational atherectomy followed by stenting is a promising strategy to reduce the restenosis rate in calcified lesions. However, the aggressive strategy is associated with an increased risk of procedural myocardial infarction.

Immediate and long-term results of elective and emergent percutaneous interventions on protected and unprotected severely narrowed left main coronary arteries

Percutaneous revascularization of protected and unprotected left main coronary arteries is associated with acceptable immediate results, but there are significant long-term consequences, including the need for repeat percutaneous intervention (10%), myocardial infarction (7.5%), coronary artery bypass surgery (7%), and death (38%), despite the elective or emergent nature of the procedure.

Acute and late clinical outcome after rotational atherectomy for complex coronary disease

Rotational atherectomy is effective acutely in treating complex coronary disease, but less is known about its long-term clinical outcome. We examined the acute results and late clinical outcome in 178 patients undergoing treatment with this device. Rotational atherectomy was used to treat 240 lesions in 178 individual patients. Nineteen percent had multilesion or staged multivessel procedures, and 71% had AHA-ACC Type B2/C lesions. The procedure was completed successfully in 94% of patients. Major complications occurred in 6% (death 1%, Q-MI 2.8%, and emergency bypass surgery 2.2%). Clinical follow-up was available for 167 (94%) patients at 13+/-6 months. Thirty-five percent required additional catheterization because of recurrent symptoms or an abnormal stress test. Clinical restenosis was confirmed in 18%, and an additional 2.2% of patients had progression of disease in previously untreated segments. At the end of 1 year, 14% had undergone repeat target vessel revascularization. Cumulatively at follow-up, approximately 80% had avoided an acute major complication and repeat revascularization for restenosis. Rotational atherectomy provides excellent acute and good late clinical results. At 1 year follow-up, the likelihood of developing clinical restenosis or significant progression of disease was 1 in 5, and patients had a 1 in 7 chance of requiring revascularization because of restenosis. These findings are encouraging and indicate that rotational atherectomy can be performed safely and with a high degree of acute and late clinical success in complex coronary disease characterized by multivessel or multilesion involvement and a predominance of B2 and C lesions.

Fracture of coronary guidewire during rotational atherectomy with coronary perforation and tamponade

We present the case of a calcified right coronary artery lesion with a 90-degree exit angle. Attempts at rotational atherectomy led to wire transection and vessel wall perforation necessitating emergent pericardiocentesis and bypass surgery. We review the literature on complications of rotational atherectomy and the management of coronary perforations and retained guidewire fragments.

Comparative early and nine-month results of rotational atherectomy, stents, and the combination of both for calcified lesions in large coronary arteries

The aim of this study was to determine the preferred treatment modality for calcified lesions in large (> or = 3 mm) coronary arteries, resulting in the largest lumen dimensions and the most favorable late clinical responses. Three hundred six lesions in 306 patients (223 men, mean age 66 +/- 11 years) were treated with either rotational atherectomy plus adjunct balloon angioplasty (n = 147), Palmaz-Schatz stents (n = 103), or a combination of rotational atherectomy plus adjunct Palmaz-Schatz stents (n = 56). The procedural success rate was 98.0% to 98.6% for each treatment modality. Minimal lumen diameter (MLD) before therapy was similar for all therapies. Final MLD after combination of rotational atherectomy plus Palmaz-Schatz stents was larger than after stent therapy or rotational atherectomy plus balloon angioplasty (3.21 +/- 0.49 mm, 2.88 +/- 0.51 mm, and 2.29 +/- 0.55 mm, respectively, p <0.0001). Correspondingly, final percent diameter stenosis was lowest after the combination of rotational atherectomy plus stent therapy, and significantly higher for stents or rotational atherectomy plus balloon angioplasty (4.2 +/- 15.3%, 14.1 +/- 13.3%, and 26.7% +/- 16.9%, respectively, p <0.0001). Event-free survival at 9 months was higher for patients treated with the combination of rotational atherectomy plus stents than either stent therapy or rotational atherectomy alone (85%, 77%, and 67%, respectively, log-rank p = 0.0633). The only significant independent predictor of an event during the 9-month follow-up period was the MLD after intervention (odds ratio 0.495, 95% confidence interval 0.308 to 0.796, p = 0.0037). We conclude that preatheroablation using rotational atherectomy, followed by adjunct stent placement for calcified lesions in large arteries, is associated with infrequent complications, the largest acute angiographic results, and the most favorable late clinical event rates.

Interrelation of coronary angiographic reference lumen size and intravascular ultrasound target lesion calcium

Intravascular ultrasound (IVUS) detects target lesion calcium twice as often as does coronary angiography. Target lesions in smaller vessels are thought to be more calcified than target lesions in large vessels. This study determined whether the presence and magnitude of target lesion calcium is related to angiographic reference lumen size. Preintervention IVUS imaging and coronary angiography were performed to study 1,454 non-aortoostial native vessel lesions in 1,342 patients. Target lesions and reference segments were evaluated according to previously published methods and are presented as mean +/- 1 SD. By angiography, 37% of lesions contained calcium, and 68% of calcium-containing lesions were classified as moderately calcified, and 32% as severely calcified. There was no relation between angiographic reference lumen size and angiographic calcium detection (p = 0.7066) or classification (none/mild vs moderate vs severe, p = 0.8135). By IVUS, 73% of lesions contained calcium. There was a consistent relation between decreasing angiographic reference lumen size and increasing IVUS lesion-associated calcium: the presence of any calcium (p = 0.0122), arc of calcium (p = 0.002), percent of lesions with an arc of calcium > 180 degrees (p = 0.0018), length of calcium (p < 0.0001), presence of any superficial calcium (p < 0.0001), arc of superficial calcium (p < 0.0001), percent of lesions with an arc of superficial calcium > 180 degrees (p = 0.0021), and length of superficial calcium (p < 0.0001). This was especially true for arteries with an angiographic reference lumen dimension < 2.00 mm. There is a distinct relation between decreasing angiographic reference lumen size and increasing lesion calcium, most striking in vessels < 2.00 mm. This increased target lesion calcium in small vessels is not seen angiographically.

Thrombosis and Hemostasis in Cardiology: Review of Pathophysiology and Clinical Practice (Part I)

The adverse consequences of thrombosis are per haps nowhere more evident than in clinical cardiology. Throm bosis and hemostasis are primary issues in the management of patients with atrial fibrillation, prosthetic heart valves, severe left ventricular dysfunction, and coronary artery disease. Clini cal trials have defined a crucial role for anticoagulation with warfarin in patients with atrial fibrillation to reduce the inci dence of stroke. Anticoagulation with warfarin and aspirin in combination offers significant protection from systemic emboli in patients with mechanical prosthetic valves, without a sub stantial increased risk of hemorrhage. The risk of systemic emboli may also be reduced by anticoagulation in patients with severe left ventricular dysfunction. Disturbance of the normal balance of hemostasis is a major factor in the pathophysiology of coronary artery disease. Antiplatelet therapy, antithrombin agents, anticoagulants, and fibrinolytic agents have been used to prevent and treat acute coronary thrombosis and to prevent reocclusion following thrombolysis and interventional therapy. Guidelines are presented for antithrombotic therapy in the prac tice of clinical cardiology.

[Rotational atherectomy: technique, indications, results]

Rotational atherectomy (Rotablation) represents one of the alternative devices to treat complex coronary artery stenoses. Rather than increasing luminal diameter by arterial stretching and plaque fracture as with balloon angioplasty, rotablation debulks atherosclerotic plaque with an abrasive diamond coated burr. The basic physical principle is differential cutting. It allows the advancing burr to selectively cut inelastic material while elastic tissue deflects away from the burr. 95% of the particles generated by the Rotablator are less than 5 microns. They are removed by the body's reticuloendothelial system. There are different strategies to perform a rotablation, regarding the number of burrs used and the final burr-to-artery ratio. An adjunctive PTCA is recommended without proof by randomized studies so far. The best indication for the Rotablator is the undilatable lesion. Lesion modification (debulking) as a method of improving vessel compliance seems to be also usefull in diffusely diseased and calcified vessels, as well as in aorto-ostial and angulated stenoses. The instent restenoses is a new indication. Randomized studies will have to proof if there is an advantage for rotablation compared to PTCA. Restenosis rates appear comparable to balloon angioplasty.

High-speed rotational atherectomy of human coronary stenoses: acute and one-year outcomes from the New Approaches to Coronary Intervention (NACI) registry

High-speed rotational atherectomy (RA) is a new percutaneous procedure for treatment of coronary stenoses that operates by the unique mechanism of plaque abrasion. This article reports acute (in-hospital) outcomes and 1-year follow-up in a large cohort of patients treated with this device by NACI investigators. A total of 525 patients with 670 lesions treated with RA form the substrate of this report. Patients tended to be older (mean age 64.8 years) than those in previously reported series of percutaneous transluminal coronary angioplasty (PTCA), with more extensive disease and more complex lesions. Calcification was present in 54% of lesions, and eccentricity in 41%. Balloon angioplasty postdilation was performed after RA in 88% of cases. Angiographic and procedural success (angiographic success without death, Q-wave myocardial infarction [MI] or emergency coronary artery bypass graft [CABG] surgery) rates were 89% and 88%, respectively. Acute in-hospital events included 4 deaths (1%) and 1 emergency CABG surgery (0.4%). MI occurred in 6% of patients, consisting predominantly of non-Q-wave MI (5%). After RA, angiographic complications included coronary dissection (12%), abrupt closure (5%), side branch occlusion (3%), and distal embolization (3%). Most of these were resolved after postdilation except for coronary dissection, which was present in 15% of lesions treated. Mean length of stay was 3 days. At 1-year follow-up, 27% of patients required target lesion revascularization and 30% had experienced death, Q-wave MI, or target lesion revascularization. Preprocedural characteristics that independently predicted 1-year death, Q-wave MI, or target lesion revascularization were male gender, high risk for surgery, target lesions that were proximal to or in bifurcations, eccentric, long, or highly stenosed. RA, even when applied to lesions of traditionally unfavorable morphology, appears to provide reasonable procedural and angiographic success rates. Restenosis and progression of disease contribute to subsequent clinical and procedural events.

Risk factors for the development of slow flow during rotational coronary atherectomy

We investigated the clinical and angiographic risk profile of slow flow during rotational atherectomy. Lesion length, angina at rest, and use of beta blockers correlated independently with slow flow in the univariate as well as in the multivariate analysis.

High-speed rotational ablation for in-stent restenosis

High-speed rotational ablation was used to treat in-stent restenosis in 10 consecutive patients with a total of 12 in-stent restenosis lesions. Seven lesions required adjunctive PTCA and five were stand alone results. No patient experienced a complication of the procedure. This small consecutive series demonstrates the feasibility of the technique and its potential application to the management of this increasingly common clinical problem.

Rotational coronary atherectomy with adjunctive balloon angioplasty: evaluation of lumen enlargement by quantitative angiographic analysis

To evaluate the mechanisms of lumen enlargement and the respective contributions of rotational coronary atherectomy (RA) and adjunctive percutaneous transluminal coronary balloon angioplasty (PTCA), serial measurements were recorded in 70 consecutive patients by quantitative coronary angiography before RA, after RA, after adjunctive PTCA, and 24 hours later. Minimal luminal diameter (MLD) increased from 0.85 +/- 0.31 mm to 1.42 +/- 0.27 mm (p < 0.001) after RA and to 2.20 +/- 0.46 mm (p < 0.001) after PTCA. Minimal luminal area (MLA) increased from 0.64 +/- 0.50 mm2 to 1.63 +/- 0.60 mm2 (p < 0.001) after RA and to 3.97 +/- 1.68 mm2 (p < 0.001) after PTCA. Both 24-hour MLD and MLA showed a trend toward reduced values (2.07 +/- 0.45 mm and 3.52 +/- 1.70 mm2, respectively) when compared with immediate results after PTCA. The absolute gains in MLD after RA and after PTCA were 0.56 +/- 0.24 mm and 0.79 +/- 0.38 mm, respectively (p < 0.01). The absolute gains in MLA after RA and after PTCA were 0.99 +/- 0.49 mm2 and 2.34 +/- 1.41 mm2, respectively (p < 0.001). The respective contributions of RA and PTCA are highly variable, but in general, balloon dilatation accounts for most of the gain in lumen area and therefore is not an adjunctive but a primary technique.

Comparison of early and recent results with rotational atherectomy

OBJECTIVES

We compared an early registry of rotational atherectomy with a recent registry to examine the evolution of patient profiles, lesion characteristics and procedural outcomes for patients treated with rotational atherectomy.

BACKGROUND

With increased experience, the selection of patients and lesions treated with a device matures. This study documents the changes in the application of rotational atherectomy.

METHODS

The patient characteristics and procedural outcomes from two multicenter patient registries-Registry I: 2,953 procedures, 3,717 lesions from 1988 to 1993; and Registry II: 200 procedures, 268 lesions from 1994-were analyzed and compared.

RESULTS

There was an increase in the average age of the patients (63 vs. 65 years, p < 0.02) and the proportion of patients with unstable angina (42.9% vs. 56.5%, p < 0.01) or previous coronary artery bypass graft surgery (18.8% vs. 24.5%, p < 0.05) in Registry II. Registry II included fewer left anterior descending coronary lesions (46.5% vs. 32.8%, p < 0.01), more type B and C lesions (83.1% vs. 91.8%, p < 0.01), more eccentric lesions (69.0% vs. 79.5%, p < 0.01) and more calcified lesions (50.3% vs. 69.4%, p < 0.01). Complications, including urgent bypass surgery, Q and non-Q wave myocardial infarction, dissection, acute occlusion and perforation, were similar in the two groups. However, mortality increased from 1.0% to 3.0% (p < 0.05) in Registry II.

CONCLUSIONS

Comparison of recent and early patients treated with rotational atherectomy revealed an increase in the complexity of patients and lesions. Although the rate of death was increased, the overall rate of major complications was not significantly changed (4.7% vs. 6.0%, p = NS).

Incidence, predictors, and consequences of coronary dissection following high-speed rotational atherectomy

The incidence of dissection following rotational atherectomy was 12.8%. By multivariate analysis tortuosity, primary and non-type B lesions were correlated with an increased incidence of dissection. The procedural success rate was reduced in the presence of dissection (86% vs 96%; p = 0.0001) primarily because patients with dissection required coronary bypass more frequently than those without dissection.

Optimal burr and adjunctive balloon sizing reduces the need for target artery revascularization after coronary mechanical rotational atherectomy

We analyzed the effect of differing burr and balloon sizes during mechanical rotational atherectomy on the need for target vessel revascularization at 6 months. The ideal burr/artery ratio and adjunctive balloon/artery ratio for optimizing acute luminal results and minimizing restenosis is unknown. Six-month clinical follow-up was obtained in 311 patients (339 lesions) treated with rotational atherectomy from August 1993 to September 1994, to determine whether procedural results or technique were related to the need for target vessel revascularization. Target vessel revascularization, defined as repeat percutaneous intervention or bypass surgery within 6 months after rotational atherectomy, occurred in 19% of patients. Larger burr/artery ratios, defined as the final burr size divided by the reference artery size, were correlated with decreased postatherectomy diameter stenosis (p <0.009) and decreased final diameter stenosis (p <0.03). However, there was no statistical association between postatherectomy or final diameter stenosis with need for revascularization (p = not significant [NS]). The need for revascularization was lowest for burr/artery ratio between 0.6 to 0.85 (15%) versus burr/artery <0.6 or >0.85 (25%) (p <0.04). Postatherectomy, smaller balloon/artery ratios, defined as the final balloon size divided by the reference artery size, were correlated with lower repeat revascularization rates. Balloon/artery ratios <0.95 (target vessel revascularization = 11% vs 25% in balloon/artery >0.95) were associated with the best luminal results and the least risk for clinical restenosis (p <0.006). For rotational atherectomy, despite improvement in acute luminal results with increased burr/artery ratio, the use of a moderate burr/artery ratio correlated with the lowest revascularization rates. There was no correlation between postatherectomy or final diameter stenosis and need for repeat interventions. However, the use of large balloon/artery ratios after rotablator was associated with higher target vessel revascularization rates.

Comparison of results of intracoronary implantation of the Plamaz-Schatz stent with conventional balloon angioplasty in chronic total coronary arterial occlusion

We compared angiographic and clinical outcomes after successful revascularization of chronic total coronary arterial occlusion with the placement of the Palmaz-Schatz stent (43 patients) and conventional balloon angioplasty (53 patients). After the procedure, the coronary stent led to a greater minimal lumen diameter than conventional balloon angioplasty (2.6 vs 1.7 mm, p < 0.001), resulting in a smaller residual stenosis (6.5% vs 36.7%, p < 0.001). At 6-month follow-up, there was no significant difference in late loss between the groups, resulting in a larger minimal lumen diameter at follow-up in the stent group (1.8 vs 1.1 mm, p < 0.001). The incidence of restenosis was lower in the stent group (27.9% vs 56.6%, p < 0.005). The frequency of the combination of myocardial infarction and coronary artery bypass graft surgery tended to be less in the stent group (2.3% vs 11.3%, P = 0.09). Placement of the Palmaz-Schatz stent improved left ventricular ejection fraction by 26% in patients who had reduced left ventricular function (p < 0.05), but conventional balloon angioplasty did not. Thus, placement of the Palmaz-Schatz stent provided a wider lumen than did conventional balloon angioplasty and, therefore, reduced the incidence of restenosis in chronic total coronary arterial occlusion. The lower restenosis rate of coronary stenting would be beneficial for long-term clinical outcome in patients with chronic total occlusion.