Intracoronary verapamil for the treatment of distal microvascular coronary artery spasm following PTCA

Coronary No-Reflow after Primary Percutaneous Coronary Intervention-Current Knowledge on Pathophysiology, Diagnosis, Clinical Impact and Therapy

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research.

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.

Short-Term Effects of Verapamil and Diltiazem in the Treatment of No Reflow Phenomenon: A Meta-Analysis of Randomized Controlled Trials

Currently, there is still a lack of an optimal treatment for no reflow phenomenon (NRP). We analyzed the efficacy and safety of using nondihydropyridine calcium channel antagonists (NDHP, verapamil/diltiazem) in patients suffering from NRP. Eight RCTs with 494 participants were eligible for analysis. The pooling analysis showed that intracoronary verapamil/diltiazem injection significantly decreased the occurrence of the coronary NRP (RR: 0.3, 95% CI: 0.16–0.57; P = 0.0002) and reduced corrected thrombolysis in myocardial infarction (TIMI) frame Count (WMD = −9.24, 95% CI −13.91–4.57; P = 0.0001) in patients with NRP. Moreover, verapamil/diltiazem treatment showed superiority in reducing wall motion index (WMI) compared to the control at day 1 (WMD = 0.11, 95% CI: 0.02–0.20; P = 0.02) (P < 0.05). There was also a significantly greater decline at occurrence of the major adverse cardiac events between verapamil/diltiazem and control groups (WMD: 0.4, 95% CI: 0.19–0.84; P = 0.02). However, using verapamil/diltiazem did not provide additional improvement of left ventricular ejection fraction post procedure (at 7 days, WMD, 0.1; 95% CI, −2.43–2.63; P = 0.94; at 30 days, WMD, 0.42; 95% CI, −2.09–2.92; P = 0.75). NDHP use is beneficial in attenuating NRP and reducing 6-month MACEs in patients with NRP.

Cerebral vasospasm

Cerebral vasospasm causes delayed ischemic neurologic deficits after aneurysmal subarachnoid hemorrhage. This is a well-established clinical entity with significant associated morbidity and mortality. The underlying patholphysiology is highly complex and poorly understood. Large-vessel vasospasm, autoregulatory dysfunction, inflammation, genetic predispositions, microcirculatory failure, and spreading cortical depolarization are aspects of delayed neurologic deterioration that have been described in the literature. This article presents a perspective on cerebral vasospasm, as guided by the literature to date, specifically examining the mechanism, diagnosis, and treatment of cerebral vasospasm.

Coronary thrombus in patients undergoing primary PCI for STEMI: Prognostic significance and management

Acute ST-elevation myocardial infarction (STEMI) usually results from coronary atherosclerotic plaque disruption with superimposed thrombus formation. Detection of coronary thrombi is a poor prognostic indicator, which is mostly proportional to their size and composition. Particularly, intracoronary thrombi impair both epicardial blood flow and myocardial perfusion, by occluding major coronary arteries and causing distal embolization, respectively. Thus, although primary percutaneous coronary intervention is the preferred treatement strategy in STEMI setting, the associated use of adjunctive antithrombotic drugs and/or percutaneous thrombectomy is crucial to optimize therapy of STEMI patients, by improving either angiographical and clinical outcomes. This review article will focus on the prognostic significance of intracoronary thrombi and on current antithrombotic pharmacological and interventional strategies used in the setting of STEMI to manage thrombotic lesions.

Pharmacotherapy During Saphenous Vein Graft Intervention

Coronary revascularization using saphenous vein grafts is an important treatment modality for patients with severe coronary artery disease. Percutaneous intervention of these grafts is often the best option for patients who develop severe stenosis of the vein grafts. Use of adjunctive glycoprotein IIb/IIIa inhibitors does not confer added benefit with ischemic endpoints as compared with heparin alone, but it increases the risk of bleeding. Bivalirudin used as the primary anticoagulant lowers the risk of bleeding. No-reflow frequently complicates vein graft interventions but can be treated with vasoactive agents such as calcium channel blockers, adenosine, and nitroprusside.

The management of thrombotic lesions in the cardiac catheterization laboratory

Plaque rupture with superimposed thrombosis is the major mechanism of acute coronary syndromes. Although angiography underestimates the presence of thrombi, their detection is a poor prognostic indicator which is proportional to their size. Although emergent percutaneous coronary intervention (PCI) in the setting of ST elevation myocardial infarction (STEMI) and early PCI in the setting of unstable angina and non-STEMI were shown to be preferred strategies, the presence of angiographic thrombosis by virtue of causing micro and macro embolization can reduce the benefit of the intervention. Antiplatelet therapy especially using glycoprotein IIb/IIIa inhibitors reduces thrombus size, and improves myocardial perfusion and ventricular function. Routine manual aspiration prior to PCI in STEMI also improves myocardial flow and reduces distal embolization and improves survival. Distal embolic protection devices and mechanical thrombectomy do not have the same clinical benefits however, rheolytic thrombectomy may have a role in large vessels with a large thrombi.

Prevention and treatment of microvascular obstruction-related myocardial injury and coronary no-reflow following percutaneous coronary intervention: a systematic approach

Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed "no-reflow." Microvascular obstruction can be broadly categorized according to the duration of myocardial ischemia preceding PCI. In "interventional MVO" (e.g., elective PCI), obstruction typically involves myocardium that was not exposed to acute ischemia before PCI. Conversely "reperfusion MVO" (e.g., primary PCI for acute myocardial infarction) occurs within a myocardial territory that was ischemic before the coronary intervention. Interventional and reperfusion MVO have distinct pathophysiological mechanisms and may require individualized therapeutic approaches. Interventional MVO is triggered predominantly by downstream embolization of atherosclerotic material from the epicardial vessel wall into the distal microvasculature. Reperfusion MVO results from both distal embolization and ischemia-reperfusion injury within the subtended ischemic tissue. Management of MVO and no-reflow may be targeted at different levels: the epicardial artery, microvasculature, and tissue. The aim of the present report is to advocate a systematic approach to prevention and treatment of MVO in different clinical settings. Randomized clinical trials have studied strategies for prevention of MVO and no-reflow; however, the efficacy of measures for reversing MVO once no-reflow has been demonstrated angiographically is unclear. New approaches for prevention and treatment of MVO will require a better understanding of intracellular cardioprotective pathways such as the blockade of the mitochondrial permeability transition pore.

Ultrahigh-dose intraarterial infusion of verapamil through an indwelling microcatheter for medically refractory severe vasospasm: initial experience

Object

Vasospasm is one of the leading causes of morbidity and death following aneurysmal subarachnoid hemorrhage (SAH). Many patients suffer devastating strokes despite the best medical therapy. Endovascular treatment is the last line of defense for cases of medically refractory vasospasm. The authors present a series of patients who were treated with a prolonged intraarterial infusion of verapamil through an in-dwelling microcatheter.

Methods

Over a 1-year period 12 patients with medically refractory vasospasm due to aneurysmal SAH were identified. Data were retrospectively collected, including age, sex, Hunt and Hess grade, Fisher grade, aneurysm location, aneurysm treatment, day of the onset of vasospasm, intracranial pressure, mean arterial pressures, intraarterial treatment of vasospasm, dosages and times of verapamil infusion, presence of a new ischemic area on CT scan, modified Rankin scale score at discharge and at the last clinical follow-up, and discharge status.

Results

Twenty-seven treatments were administered. Between 25 and 360 mg of verapamil was infused per vessel (average dose per vessel 164.6 mg, range of total dose per treatment 70–720 mg). Infusion times ranged from 1 to 20.5 hours (average 7.8 hours). The number of treated vessels ranged from 1 to 7 per patient. The number of treatments per patients ranged from 1 to 4. There was no treatment-related morbidity or death. Blood pressure and intracranial pressure changes were transient and rapidly reversible. Among the 36 treated vessels, prolonged verapamil infusion was completely effective in 32 cases and partially effective in 4. Only 4 vessels required angioplasty for refractory vasospasm after prolonged verapamil infusion. There was no CT scanning evidence of new ischemic events in 9 of the 12 patients treated. At last clinical follow-up 6–12 months after discharge, 8 of 11 patients had a modified Rankin Scale score ≤2.

Conclusions

Prolonged intraarterial infusion of verapamil is a safe and effective treatment for medically refractory severe vasospasm and reduces the need for angioplasty in such cases.

CONTROVERSIES IN THE ENDOVASCULAR MANAGEMENT OF CEREBRAL VASOSPASM AFTER INTRACRANIAL ANEURYSM RUPTURE AND FUTURE DIRECTIONS FOR THERAPEUTIC APPROACHES

CEREBRAL VASOSPASM IS one of the leading causes of morbidity and mortality after aneurysmal subarachnoid hemorrhage. Despite maximal medical therapy, however, up to 15% of patients surviving the ictus of subarachnoid hemorrhage experience stroke or death from vasospasm. For those cases of vasospasm that are refractory to medical treatment, endovascular techniques are frequently used, including balloon angioplasty with or without intra-arterial infusion of vasodilators, combined endovascular modalities, and aortic balloon devices. In this article, we review each of these therapies and their expanding role in the management of this condition. Moving forward, rigorous prospective outcome assessments after endovascular treatment of cerebral vasospasm are necessary to clearly delineate the efficacy and indications for these techniques.

Advances in vasospasm treatment and prevention

Outcome after aSAH depends on several factors, including the severity of the initial event, perioperative medical management, surgical variables, and the incidence of complications. Cerebral vasospasm (CV) is ure to consistently respond to treatment, emphasizing the need for further research into the underlying mechanisms of SAH-induced cerebrovascular dysfunction. To this end, our paper reviews the relevant literature on the main therapies employed for CV after aSAH and discusses possible avenues for future investigations. Current management of this condition consists of maximal medical therapy, including triple H regimen and oral administration of calcium antagonists, followed by endovascular balloon angioplasty and/or injection of vasodilatory agents for refractory cases. As the precise pathophysiology of CV is further elucidated, the development of promising investigational therapies will follow.

Effect of intraarterial verapamil on the diameter of vasospastic intracranial arteries in patients with cerebral vasospasm

Object

This study was conducted to determine whether there is a change in intracranial arterial diameters after verapamil infusion for vasospasm and, if it is present, to determine whether the change occurs in proximal, intermediate, or distal vessels.

Methods

The authors measured arterial diameters in all patients treated with intraarterial verapamil at their institutions between August 2003 and September 2004. In all, 18 treatments were examined in 15 patients. Measurements were made before and after verapamil infusion in a blinded fashion with the aid of a magnification loupe at nine predetermined arterial sites on each angiogram. Baseline arterial measurements were made on each patient's initial angiogram and on the angiogram demonstrating spasm prior to endovascular therapy as well in 14 of the patients. Charts were retrospectively reviewed to determine whether the patients benefited from intraarterial vera-pamil.

From the time of the initial angiogram to the time of vasospasm, there was a 21.6% decrease (p = 0.092) in proximal artery diameter, a 47.1% decrease (p < 0.05) in intermediate artery diameter, and a 12.4% decrease (p < 0.05) in distal artery diameter. There were no significant changes in the diameters of proximal, intermediate, or distal vessels after verapamil infusion (mean dose 7.4 mg, range 2.5–10 mg). After infusion of intraarterial verapamil, the proximal vessels showed a 1.1% decrease in diameter, the intermediate vessels showed a 9.4% increase, and the distal vessels showed a 3.3% decrease.

Conclusions

Administration of intraarterial verapamil does not cause a significant increase in the diameter of vasospastic vessels at the administered doses.

Mechanical protection of cardiac microcirculation during percutaneous coronary intervention of saphenous vein grafts

Saphenous vein bypass grafts permeability is one of the most important limitations of open heart surgery. The risks associated with surgical re-intervention are greater than those associated with the initial procedure. While native coronary arteries usually have fixed, fibrotic or calcified atherosclerotic plaques, the disease in the vein grafts contains soft material. When this material is compressed during percutaneous angioplasty, there is an unfavorable immediate outcome due to distal embolization of thrombus and plaque debris. In addition, the risk of post-procedure adverse events are higher when the grafts have a long time of implantation, due to a greater risk of branch occlusion or no-reflow at the adjacent microcirculation. The clinical consequence is a Non-Q-Wave Myocardial Infarction that is reflected in the increased serum cardiac enzymes. It is because of this complication that the distal protection devices were developed. The purpose of this paper is to review and discuss the current data on the distal protection devices available now for the treatment of degenerative saphenous vein graft disease. Currently, there are two distal protection devices approved in the United States: the Guardwire Balloon and Aspiration (Export) System and the Filter Wire EX. Other devices like the Triactiv System, Angioguard XP/ECW, DOW, MedNova Cardioshield, Medtronic-AVE DPD and the E-Trap Filter are still being studied. The first observational studies showed the safety and efficacy of the approved devices. A large randomized trial initially confirmed a significant decrease of in-hospital and 30-day cardiac adverse events, mainly Non-Q-Wave Myocardial Infarction, when angioplasty was performed with the assistance of the Guardwire System. Subsequently, another randomized study showed an equivalence between the Guardwire System and the Filter Wire EX. Distal protection devices have an acceptable performance, however, further technological improvements are warranted for a quick preparation, delivery and/or retrieval of these devices.

Differential release of cardiac enzymes after percutaneous coronary intervention

We hypothesized that using calcium channel blockers (CCBs) that dilate microvasculature during percutaneous coronary intervention (PCI) would result in lower postprocedural creatine phosphokinase (CPK). PCI can be complicated by elevated CPK that has been associated with impaired microvascular perfusion. Nitroglycerin (NTG), the conventional PCI vasodilator, dilates epicardial arteries but does not affect the microvasculature. We hypothesized that using CCBs that dilate the microvasculature would result in lower postprocedural CPK values. Patients (n = 816) without evidence of acute myonecrosis undergoing PCI were divided into two groups based on whether they received intracoronary NTG or CCB during PCI. Postprocedural CPK values were compared using a repeated-measures ANOVA and a random coefficient model. By repeated-measures analysis, the NTG group had CPK values of 88%, 83%, and 89% of the CCB group's CPK values at < 8, 8-14, and > 14 hr after PCI (P = 0.0080, 0.0002, and 0.0244), respectively. In a random coefficient model, the NTG group had CPK values 84%, 84%, and 89% of the CCB group's mean CPK values at 6, 12, and 18 hr after PCI (P = 0.0003, 0.0006, and 0.0403), respectively. Peak CPK values occurred earlier with CCB, although the maximal CPK was similar in both groups. Intracoronary CCB use is associated with an accelerated release of CPK after PCI compared with NTG. This is consistent with more efficient relief of microvascular obstruction with CCB. It suggests that myonecrosis may originate with vascular trauma at the time of PCI and its enzymatic expression is modifiable with different vasodilators.

Coronary Hyperemic Dose Responses of Intracoronary Sodium Nitroprusside

Background— Sodium nitroprusside is one of several agents considered effective for treating the no-reflow phenomenon during acute coronary interventions. However, the coronary hyperemic dose responses and systemic hemodynamic effects of intracoronary nitroprusside have yet to be determined in humans. The purpose of this study was to compare the hyperemic and hemodynamic responses of intracoronary nitroprusside to intracoronary adenosine in patients during cardiac catheterization with angiographically normal anterior descending arteries.

Methods and Results— In 21 patients, coronary blood flow velocity (0.014-inch Doppler flow wire), heart rate, and blood pressure were measured in unobstructed left anterior descending coronary arteries at rest, after intracoronary adenosine (30- to 50-μg boluses), and after 3 serial doses (0.3-, 0.6-, and 0.9-μg/kg boluses) of intracoronary nitroprusside. Coronary reserve was calculated as hyperemia/basal coronary flow velocity. In an additional 9 patients with intermediate stenoses (53±7%), 14 fractional flow reserve (FFR) measurements (using 0.014-inch pressure wire) were performed with both intracoronary adenosine and nitroprusside (0.6 μg/kg). Intracoronary nitroprusside produced equivalent coronary hyperemia with a longer duration (≈25%) compared with intracoronary adenosine. Intracoronary nitroprusside (0.9 μg/kg) decreased systolic blood pressure by <20%, with minimal change in heart rate, whereas intracoronary adenosine had no effect on these parameters. FFR measurements with intracoronary nitroprusside were identical to those obtained with intracoronary adenosine ( r =0.97).

Conclusions— Compared with adenosine, intracoronary nitroprusside produces an equivalent but more prolonged coronary hyperemic response in normal coronary arteries. Intracoronary nitroprusside, in doses commonly used for the treatment of the no-reflow phenomenon, can produce sustained coronary hyperemia without detrimental systemic hemodynamics. On the basis of FFR measurements compared with adenosine, sodium nitroprusside also appears to be a suitable hyperemic stimulus for coronary physiological measurements.

Effect of intracoronary estradiol on postischemic microvascular damage in a porcine model: a myocardial contrast echocardiographic study

Coronary microvascular damage can occur in the presence of myocardial ischemia even if epicardial vessels are patent, a phenomenon known as "no-reflow." Estrogens have favorable effects on coronary conductance and resistance arteries, and may have therapeutic value in ischemic syndromes. Myocardial contrast echocardiography (MCE) is a promising method for evaluating microvascular damage. In this study, the authors hypothesized that acute intracoronary 17beta-estradiol administration can reduce postischemic microvascular damage, which is evaluated by MCE, in a porcine model. Sixteen male pigs were randomized into 2 groups: the treatment group (n = 9) received intracoronary estradiol in increasing doses, and the control group (n = 7) received intracoronary vehicle (dimethylsulfoxide, DMSO). Microvascular damage was induced by balloon catheter occlusion followed by reperfusion of the left circumflex coronary artery (LCX). MCE using Levovist with harmonic imaging was performed before and during 15-minute balloon occlusion of the proximal LCX to determine perfusion areas of the left anterior descending artery (LAD) and LCX. MCE was performed immediately postocclusion and after each injection of estradiol (1, 10, and 100 nmol/L) or DMSO. Videodensitometry measurements were performed as a quantitative marker for myocardial microvascular damage. Videodensitometry results were expressed as peak intensity ratios. Intracoronary estradiol induced a significant reduction in myocardial microvascular damage after ischemic episode by videodensitometry measurements when compared to intracoronary DMSO. The authors conclude that intracoronary injection of estradiol reduces postischemic microvascular damage measured by MCE in a porcine model.

Comparison of the vasodilating effect of nitroglycerin, verapamil, and tolazoline in hand angiography

PURPOSE

To compare the vasodilating effect and safety of intraarterial verapamil with the long-accepted standard vasodilators nitroglycerin and tolazoline in hand angiography.

MATERIALS AND METHODS

The authors studied 25 patients who underwent brachial artery angiography. In 22 cases, there was poor or moderate visualization of the forearm and hand vasculature. To improve blood flow to the periphery, subsequent angiograms with intraarterial vasodilating agents were obtained. First, nitroglycerin was administered (n = 22). In cases of continuous poor or moderate visualization of the forearm and hand vasculature, another angiogram was obtained with verapamil (n = 21). If opacification remained poor or moderate, eventually tolazoline was injected (n = 20). To avoid pharmacologic interactions of the different vasodilating drugs, a minimum 15-minute interval between series was observed. The degree of opacification of the forearm and hand arteries was graded on a scale from 1 to 5: visualization of the forearm arteries only was defined as 1, of the forearm arteries and superficial/deep palmar arch as 2, of the forearm arteries, superficial/deep palmar arch, and digital arteries to the level of the metacarpophalangeal joints as 3, to the level of the proximal interphalangeal joints as 4, and to the distal interphalangeal joints as 5.

RESULTS

All three vasodilating agents demonstrated highly significant improvement in blood flow; verapamil and tolazoline showed statistically greater effects than nitroglycerin. Verapamil caused the fewest and least severe adverse effects.

CONCLUSION

Intraarterial verapamil and tolazoline are comparable in terms of vasodilatory efficacy in hand arteries. However, because of its favorable adverse effect profile, verapamil is recommended for optimizing visualization of the peripheral arterial vascular system.

Effect of percutaneous coronary interventions for in-stent restenosis in degenerated saphenous vein grafts without distal embolic protection

OBJECTIVES

This study was designed to investigate the impact of percutaneous coronary interventions (PCIs) in degenerated saphenous vein grafts (SVGs) without distal embolic protection.

BACKGROUND

Distal embolic protection devices have been shown to reduce the incidence of no reflow/slow flow during PCI of de novo lesions in degenerated SVGs. It is unclear whether PCI of in-stent restenosis (ISR) lesions in degenerated SVGs is associated with no reflow/slow flow and whether distal embolic protection is beneficial in these cases as well.

METHODS

We studied 54 consecutive patients with treated ISR lesions in degenerated SVGs who underwent PCI without distal embolic protection in a single center. Procedural and in-hospital outcomes were examined. The average age was 71 +/- 8 years; 32% of the patients had diabetes. The mean lesion length was 13 +/- 6 mm and the procedural success rate was 98% (53/54). Cutting balloon angioplasty was used in 46% (25/54) of cases, and a new stent was inserted in 46% (25/54) of patients. Gamma brachytherapy was performed in 19% (10/54) of patients. During the procedure there were no episodes of no reflow/slow flow, and there were no patients with in-hospital Q-wave or non-Q-wave myocardial infarction. There was one in-hospital noncardiac death.

CONCLUSIONS

In this consecutive series of patients with ISR of degenerated SVGs undergoing PCI without distal protection, there were no episodes of slow flow/no reflow and no procedure-related myocardial infarctions. It appears that distal embolic protection may not be necessary during PCI of ISR lesions in degenerated SVGs.

Can the premises of the spasm of resistance vessel concept permit improvement in the treatment and prevention of ischemic heart disease?

In this communication, the spasm of resistance vessel (S-RV) concept of ischemic heart disease (IHD) and other ischemic will be reviewed and updated, and evidence will be presented that principles of the hypothesis might improve the treatment and prevention of IHD. The S-RV concept provides a different basic pathogenetic framework for IHD, and suggestions for treatment and prevention stem from its different basic conceptualization of this disorder. The concept asserts that S-RV directly induces symptoms in IHD, and this position challenges the accepted pathogenetic mechanism for this disorder, i.e., that symptoms in IHD are due directly to obstructive occlusions of epicardial arteries secondary to coronary artery disease. The S-RV concept avers that ischemia-induced S-RV is a major factor in IHD, and evidence supporting this position is provided. Another major position of the hypothesis is that no-reflow (reduced flow after infarction and severe myocardial ischemia in the absence of infarction) is due to ischemic injury-induced S-RV, and a variety of evidences to support this position are offered.Proposed improvement in the treatment of IHD is based mainly on treating ischemia-induced S-RV. alpha-Adrenergic sympathetic blockade reverses ischemia-induced S-RV, and alpha-adrenergic blockade is suggested as therapy for acute coronary syndromes and to prevent complications of percutaneous coronary interventions. Also, angiotensin-converting enzyme inhibition, which has actions similar to alpha-adrenergic blockade, is also suggested. Proposals for the prevention of IHD are based the prevention of S-RV, and special emphasis is given to preventing exercise- and stress-related IHD.

Intracoronary verapamil for reversal of no-reflow during coronary angioplasty for acute myocardial infarction

No-reflow is a frequent observation during direct PTCA for acute myocardial infarction (AMI) and associated with a poor clinical outcome. This study assesses the value of verapamil for reversal of no-reflow during PTCA for AMI. In a consecutive series of 212 direct or rescue PTCAs for AMI, a TIMI flow grade < 3 was observed in 23 patients (10.8%). Ten of these patients had received GP IIb/IIIa antagonists before PTCA. Seven patients with AMI and TIMI grade 3 flow served as controls. All lesions were treated by stents. In 18 patients with systolic blood pressure > 90 mm Hg, nitroglycerine (0.1 mg i.c.) was given. Verapamil (1 mg over 2 min) was given via an infusion catheter distal to the angioplasty site. Before and after nitroglycerine, after verapamil, and 15 min later coronary flow was assessed by the TIMI frame count method (TFC). Nitroglycerine had no effect on TFC. Verapamil reduced TFC from 56 +/- 9 frames to 24 +/- 4 (P < 0.001). In controls, TFC did not change significantly. The TIMI flow grade was restored to TIMI flow grade 3 in 65%. In two of seven right coronary and one of three circumflex arteries, intermittent AV block II occurred during verapamil injection, which disappeared after atropine. No-reflow after PTCA for AMI can be reversed by intracoronary verapamil. This supports the hypothesis that no-reflow is caused by acute microvascular dysfunction probably because of a disorder in calcium homeostasis or microvascular spasm.

Treatment of no-reflow and impaired flow with the nitric oxide donor nitroprusside following percutaneous coronary interventions: initial human clinical experience

OBJECTIVES

The objective of this study was to test the hypothesis that the intracoronary administration of a direct donor of nitric oxide is a safe and effective method to treat impaired blood flow (no-reflow phenomenon) that occurs during percutaneous transluminal coronary interventions (PTCI).

BACKGROUND

The absence of blood flow or decreased blood flow in a coronary artery following PTCI despite the presence of a patent epicardial vessel or graft is designated "no-reflow" or "impaired flow." This alteration in blood flow is a serious complication of percutaneous revascularization strategies that results in an increased incidence of morbidity, myocardial infarction and mortality.

METHODS

Nineteen consecutive patients undergoing standard percutaneous revascularization procedures complicated by either no-reflow or impaired flow that received intracoronary nitroprusside treatment were studied. One patient had two procedures performed on two separate grafts on two successive days. Interventions were performed on either saphenous vein grafts or native vessels and utilized angioplasty, stent deployment or rotational atherectomy strategies. Following interventions that were associated with impaired flow, varying total doses (of nitroprusside 50 to 1,000 microg) were administered into the coronary artery or saphenous vein graft. The angiographic archives before and after intracoronary administration of nitroprusside were analyzed for TIMI grade flow and a frame count method was used to quantitate blood flow velocity.

RESULTS

Following a PTCI that resulted in either no-reflow or impaired flow, nitroprusside (median dose 200 microg) was found to lead to a highly significant and rapid improvement in both angiographic flow (p < 0.01 compared with pretreatment angiogram) and blood flow velocity (p < 0.01 compared with pretreatment angiogram). No significant hypotension or other adverse clinical events were associated with nitroprusside administration.

CONCLUSIONS

The direct nitric oxide donor nitroprusside is an effective, safe treatment of impaired blood flow and no-reflow associated with PTCI. The use of nitroprusside to treat syndromes secondary to microvascular dysfunction may provide a novel therapeutic strategy for treating no-reflow or impaired blood flow following percutaneous interventions.

Successful management of right coronary air embolus after intracoronary administration of verapamil

A case of a 50 year-old male with a coronary air embolism is described. The case was successfully treated with intracoronary administration of verapamil.

Assessing the relation between coronary reflow and myocardial reflow

Since the recognition that prompt reperfusion of the infarct-related artery decreases mortality after acute myocardial infarction (MI), we have been interested in optimizing therapeutic regimens to accelerate the establishment of infarct-related artery patency. Although the major endpoint of many angiographic trials has been the acquisition of a patent infarct-related artery, this may not correlate with actual tissue perfusion because of the no-reflow phenomenon. With myocardial contrast echocardiography (MCE), we assessed the success of myocardial reperfusion at the microvascular level in patients with an acute anterior MI. We documented that 21% of the study patients exhibited Thrombolysis in Myocardial infarction (TIMI) grade 2 flow after coronary angioplasty, and all of them showed substantial "no reflow" on MCE. Conversely, no reflow was observed on MCE in only 16% of patients with TIMI grade 3 flow. Early TIMI grade 3 flow resulted in a significantly better left ventricular functional outcome compared with those with TIMI grade 2. In view of microvascular perfusion, TIMI grade 2, despite the absence of coronary obstruction, cannot be regarded as successful reperfusion. Our study, using a Doppler guidewire probe, documented the specific coronary flow pattern in patients with TIMI grade 2. Patients with TIMI grade 3 flow exhibited systolic antegrade flow followed by the predominant diastolic flow. TIMI grade 2 flow represented features of a to-and-fro coronary flow velocity pattern. This latter is characterized by (1) the abnormal retrograde flow in the early systole; (2) the reduction in the systolic antegrade flow; and (3) the rapid deceleration of the diastolic flow velocity. This pattern would be explained by an increase in vascular impedance and a decrease in myocardial blood volume.

Beneficial effect of intracoronary verapamil on microvascular and myocardial salvage in patients with acute myocardial infarction

OBJECTIVES

We assessed the acute effect of intracoronary injection of verapamil on microvascular function after primary percutaneous translumanal coronary angioplasty (PTCA) for acute myocardial infarction (AMI) with myocardial contrast echocardiography (MCE) in relation to functional outcomes.

BACKGROUND

Recent clinical studies have documented the potential of verapamil for possible increase in coronary blood flow after primary PTCA.

METHODS

Forty patients with a first AMI were randomly assigned to the verapamil group (n = 20) or the control group (n = 20). In the verapamil group, verapamil (0.5 mg) was injected into the infarct-related artery shortly after PTCA, followed by the oral administration. We performed MCE with an intracoronary injection of sonicated microbubbles before and after verapamil. To assess microvascular integrity, we determined the baseline-subtracted peak intensity in the risk area and the ratio of the no reflow zone plus the low reflow zone to the risk area (low reflow ratio). We determined the average wall motion score (dyskinesia/akinesia = 3; normal = 0) in the risk area on the day of AMI and a mean of 24 days later.

RESULTS

The low reflow zone was observed shortly after PTCA in 14 verapamil group patients, and the low reflow ratio decreased after verapamil (0.39 +/- 0.23 vs. 0.29 +/- 0.17 [mean +/- SD], p < 0.05). Peak intensity significantly (p < 0.05) increased from 6 +/- 5 to 12 +/- 6 after verapamil. The reduction in wall motion score from the acute (day -1) to the late stage (day -24) was significantly greater in the verapamil group than in the control group (0.7 +/- 0.8 vs. 0.2 +/- 1.3, respectively, p < 0.05).

CONCLUSIONS

Intracoronary administration of verapamil after primary PTCA can attenuate microvascular dysfunction and thereby augment myocardial blood flow in patients with AMI, leading to better functional outcome than with PTCA alone.

Abrupt vessel closure: changing importance, management, and consequences

Percutaneous coronary interventions have been performed for 20 years. Despite the success and progress of these interventions, abrupt vessel closure has been a dramatic adverse event of coronary interventions. Closure has frequently led to the major complications of death, myocardial infarction, and emergency coronary artery bypass. Because of the fear of this adverse event and its subsequent complications, the applicability of coronary interventions is sometimes limited. The pathologic characteristics of abrupt vessel closure have been recognized as predominantly caused by dissection, with vessel recoil and thrombus formation playing important secondary roles. The recognition of the lesions at risk for abrupt vessel closure has led to a strategy of lesion-specific device therapy to reduce complications. Similarly the role of antiplatelet and antithrombotic therapies have reduced complications. The earliest methods of dealing with abrupt closure was emergency coronary artery bypass surgery with significant rates of morbidity and mortality. With the advent of second-generation devices and techniques, particularly stents, the management of abrupt vessel closure has been simplified and alternatives to emergency coronary bypass are more available. This article will review the history and current status of the prevention and management of abrupt vessel closure and demonstrate that anticipation and management of this complication have been facilitated with reduction of subsequent complications and increased applicability of coronary interventions.

A case of rest angina due to microvascular spasm

A 66-year-old woman underwent elective cardiac catheterization for investigation of periodic attacks of chest pain at rest. During the examination, a chest pain attack occurred unexpectedly, resulting in ST elevation in the precordial leads on electrocardiography. Immediate coronary arteriography demonstrated no organic stenosis but markedly delayed contrast medium perfusion in the mild to distal portion of the left anterior descending artery. These phenomena spontaneously disappeared about 3 min later, and the patient was diagnosed as having angina pectoris due to microvascular spasm. The demonstration of angina pectoris due to microvascular spasm by coronary arteriography during a spontaneous attack is very rare.

Treatment of no-reflow in degenerated saphenous vein graft interventions: comparison of intracoronary verapamil and nitroglycerin

No-flow has been reported after 10-15% of percutaneous interventions on degenerated saphenous vein grafts. In this prospective study of 36 degenerated saphenous vein graft lesions (32 patients), no-flow (TIMI flow < 3 in the absence of a significant lesion or dissection) occurred in 15/36 (42%) lesions. A total of 32 episodes of no-flow occurred after angioscopy (n = 14), extraction atherectomy (n = 10), balloon angioplasty (n = 2) or stent implantation (n = 6). Intragraft nitroglycerin (100-300 micrograms) alone resulted in no improvement in TIMI flow in the setting of no-reflow (TIMI flow 1.2 +/- 0.6 to 1.4 +/- 0.8, P = NS). Intragraft verapamil (100-500 micrograms) resulted in improvement in flow in all 32 episodes (TIMI flow 1.4 +/- 0.8 before, to 2.8 +/- 0.5 after verapamil, P < 0.001). Although verapamil increased TIMI flow after all episodes of no-reflow, two (6.3%) had persistent no-reflow (TIMI 1) despite verapamil, associated with non-Q wave myocardial infarction. In conclusion, treatment of no-reflow with verapamil during degenerated vein graft interventions was associated with reestablishment of TIMI 3 flow in 88% of cases. In contrast, intragraft nitroglycerin alone was ineffective for reversing no-reflow.

Distal vessel pullback angiography and pressure gradient measurement: an innovative diagnostic approach to evaluate the no-reflow phenomenon

The angiographic appearance of "no-reflow" in saphenous vein grafts or native coronary arteries has been described following administration of thrombolytic therapy or performance of percutaneous transluminal coronary angioplasty or atherectomy. Apparent occlusion may represent spasm, dissection, thrombosis, or competitive collateral circulation, all of which must be excluded to make the diagnosis of "no-reflow." We describe an innovative approach to the diagnostic dilemma created by the appearance of "no-reflow" at coronary angiography. Pressure gradient measurement with distal vessel pull-back (retrograde) angiography provides maximal information regarding the severity of disease and the etiology of "no-reflow," while exposing both the patient and angiographer to less risk compared to standard strategies.

Transcatheter therapy of thrombotic-occlusive lesions in saphenous vein grafts

Saphenous vein graft (SVG) disease, a form of accelerated atherosclerosis, remains a therapeutic conundrum. The use of stents after excluding the presence of thrombus has proved highly successful at short- and long-term follow-up. We report on 60 severely symptomatic patients with multiple subtotal and total thrombotic SVG occlusions who were treated with a combination of intragraft urokinase-verapamil infusion and insertion of multiple biliary stents. Stent deployment had a 100% success rate. No case of clinical subacute thrombosis was registered, and major in-hospital complications were uncommon (<1%). The clinical outcome was encouraging, with a 12-month event-free survival rate of 87% in the 57 evaluable patients. This method of therapy appears to be highly successful in the treatment of thrombus-containing occlusive SVG disease, in preventing the "no-reflow" phenomenon, and in lessening the incidence of periprocedural non-Q-wave myocardial infarction.

Myocardial perfusion patterns related to thrombolysis in myocardial infarction perfusion grades after coronary angioplasty in patients with acute anterior wall myocardial infarction

BACKGROUND

Epicardial coronary flow is occasionally reduced even after coronary intervention despite the absence of vessel obstruction in patients with acute myocardial infarction. Our aim was to clarify the cause and outcomes of radiocontrast slow filling in patients with reperfused acute anterior myocardial infarction by assessing microvascular damage with the use of myocardial contrast echocardiography (MCE) and functional outcomes.

METHODS AND RESULTS

We carefully reviewed the cineangiograms of 86 patients who achieved coronary revascularization within 12 hours of the onset and underwent MCE before and soon after recanalization with the intracoronary injection of sonicated microbubbles. Antegrade coronary flow after recanalization was graded by two observers based on Thrombolysis in Myocardial Infarction (TIMI) trial flow grades. Left ventricular ejection fraction was measured on the day of infarction and 1 month later. TIMI grade 2 was observed in 18 patients (21%), and the other 68 patients manifested TIMI grade 3 after recanalization. All patients with TIMI 2 showed substantial MCE no reflow, whereas only 11 patients (16%) with TIMI 3 showed MCE no reflow. Functional improvement was worse in patients with TIMI 2 than in those with TIMI 3 (TIMI 2, 38 +/- 8% versus 40 +/- 8%, P = NS [acute versus late]; TIMI 3, 44 +/- 13% versus 55 +/- 13%, P < .001). Among patients with TIMI 3, significant functional improvement was observed only in patients with MCE reflow (MCE reflow, 46 +/- 13% versus 57 +/- 12%, P < .001; MCE no reflow, 35 +/- 11% versus 45 +/- 12%, P = NS).

CONCLUSIONS

Despite no obstructive lesion of the vessel, TIMI 2 is caused by advanced microvascular damage and is a highly specific, although not sensitive, predictor of poor functional outcomes in patients with acute myocardial infarction. TIMI 3 does not necessarily indicate myocardial salvage, and detection of MCE no reflow in these patients is particularly useful for the prediction of functional outcome.

Guide wire-induced coronary artery spasm during percutaneous transluminal coronary angioplasty. A case report

Coronary artery spasm induced by a guide wire is a very rare complication of percutaneous transluminal coronary angioplasty (PTCA). The authors describe a patient who developed coronary vasoconstriction distal to the dilated lesion during PTCA, which was refractory to intracoronary nitroglycerin and intravenous calcium antagonist injection and balloon angioplasty but responded promptly and completely to withdrawal of the guide wire from the coronary artery, suggesting that the spasm had been induced by the guide wire.

Clinical effects and utility of intracoronary diltiazem

Coronary artery spasm is a known complication of coronary interventions, for which intracoronary nitroglycerin (ICN) is the treatment of choice. Some forms of intense spasm are resistant to ICN. Calcium channel antagonists are also known to be effective for coronary artery spasm, including nitroglycerin-resistant spasm. Here we describe a protocol for the clinical use of intracoronary diltiazem (ICD). By this protocol, ICD can be safely given without disturbing the clinical status of patients. ICD (2.5 mg) given slowly over 1 minute produced no vasodilitation of normal vessel segments but did produce significant dilatation of stenotic segments above and beyond the effects of nitrates. Mean minimum lumen diameter increased 18%, from 0.89 +/- 0.06 mm to 1.06 +/- 0.07 mm (mean +/- SEM, P < 0.001). ICD produced clinically insignificant changes in systolic blood pressure, diastolic blood pressure, heart rate, and PR, QRS, and QT intervals. This protocol has been employed to safely use ICD to relieve both nitroglycerin-resistant epicardial artery spasm and nitroglycerin-resistant distal microvascular spasm (the no-reflow phenomenon).

Perfusion therapy to reduce myocardial ischemia en route to emergency coronary artery bypass grafting for failed percutaneous transluminal coronary angioplasty

Despite improvements in operator technique, catheter technology, and the development of new devices, emergency coronary artery bypass grafting (CABG) is still required in 1%-4% of attempted catheter based revascularization procedures. Patients who require such emergency CABG after failed percutaneous transluminal coronary angioplasty (PTCA) have worse acute outcomes than those undergoing elective CABG, with a higher incidence of Q wave myocardial infarction (MI) and a higher operative mortality. In patients with otherwise refractory abrupt closure, maintenance of antegrade coronary blood flow using perfusion catheters lessens the incidence of Q wave MI and lowers peak creatinine phosphokinase. Direct maintenance of coronary flow thus appears to provide more definitive control of myocardial ischemia than purely adjunctive measures, such as intra-aortic balloon pumping, cardiopulmonary support, or coronary sinus retroperfusion. Although the recent introduction of coronary stents holds great promise for definitive percutaneous reversal of abrupt closure and a dramatic decrease in the incidence of emergency CABG for failed PTCA, maintenance of antegrade flow via perfusion technology remains the cornerstone of management in reducing the perioperative mortality and morbidity of patients who still require emergency bypass surgery after failed PTCA.

Features and outcome of no-reflow after percutaneous coronary intervention

No-reflow is an uncommon complication that may occur after revascularization of patients with acute myocardial infarction, after interventions in saphenous vein bypass grafts, and after the use of some new interventional devices. However, the clinical impact of no-reflow after coronary intervention is unknown. Accordingly, this study examined the incidence, clinical presentation, angiographic characteristics, and outcome of no-reflow after percutaneous coronary intervention. No-reflow was defined as an acute reduction in antegrade flow (< or = 1, as defined by the Thrombolysis in Myocardial Infarction [TIMI] trial) not attributable to abrupt closure, high-grade stenosis, or spasm of the original target lesion. Among 10,676 coronary interventions performed between October 1988 and June 1993, no-reflow occurred in 66 patients (0.6%). These patients were compared with a subgroup of 500 consecutive patients who did not exhibit no-reflow. The incidence of no-reflow was 30 of 9,431 (0.3%) for percutaneous transluminal coronary angioplasty, 1 of 317 (0.3%) for excimer laser, 8 of 104 (7.7%) for Rotablator (Heart Technologies, Bellevue, Washington), 21 of 469 (4.5%) for extraction atherectomy, and 6 of 355 (1.7%) for directional atherectomy. Compared with those without no-reflow, patients with no-reflow experienced a 10-fold higher incidence of in-hospital death (15%) and acute myocardial infarction (31%). Correlates of in-hospital mortality included acute myocardial infarction on presentation (p = 0.006) and final flow < 3 (as defined by the TIMI trial) at completion of the procedure (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence and treatment of 'no-reflow' after percutaneous coronary intervention

BACKGROUND

Profound reduction in antegrade epicardial coronary flow with concomitant ischemia is seen occasionally during percutaneous coronary intervention despite the absence of evident vessel dissection, obstruction, or distal vessel embolic cutoff. In a prior small series of cases, this "no-reflow" phenomenon appeared to be promptly reversed by the intra-coronary administration of verapamil.

METHODS AND RESULTS

To further understand the prevalence of this syndrome and its responsiveness to the proposed therapy, we reviewed 1919 percutaneous interventions performed between January 1991 and April 1993. During the study period, 39 patients (2.0%) met our criteria for no reflow, 37 of whom were treated with intracoronary nitroglycerin followed by intracoronary verapamil and 2 of whom received intracoronary nitroglycerin alone. An additional 16 patients (0.8%) were given verapamil as part of the management of a flow-limiting dissection or distal embolus (mechanical obstruction). Intracoronary verapamil (50 to 900 micrograms, total dose) improved TIMI flow grade in 89% of no-reflow patients and markedly reduced the number of cineframes between contrast injection and opacification of a selected distal landmark (from 91 +/- 56 to 38 +/- 21 frames, P < .001). By contrast, only 19% of patients with epicardial mechanical obstruction showed improvement in TIMI flow grade after verapamil, with minimal reduction in frames to opacification (from 107 +/- 42 to 101 +/- 69, P = .73).

CONCLUSIONS

The no-reflow phenomenon--reduction in distal flow without apparent dissection or distal embolization--occurs in 2% of coronary interventions. It generally responds promptly to intracoronary verapamil administration, suggesting that distal microvascular spasm may be its etiology.

Palmaz-Schatz stenting for treatment of focal vein graft stenosis: immediate results and long-term outcome

OBJECTIVES

This study aimed to evaluate the effectiveness of Palmaz-Schatz stenting for the treatment of saphenous vein graft stenoses.

BACKGROUND

Failure of saphenous vein grafts is a common cause of recurrent ischemia after coronary bypass surgery. A second bypass surgery carries more risk than the initial procedure, and balloon angioplasty of vein grafts has yielded disappointing results. It has been hoped that stenting might offer a better treatment option.

METHODS

We examined the results of stent placement in 200 saphenous bypass graft lesions consecutively treated with either coronary (n = 146) or biliary (n = 54) Palmaz-Schatz stents. Immediate outcome and clinical follow-up (median 15.5 months) were examined in all patients. To document angiographic outcome, a second angiography was performed at 3 to 6 months for the first 120 consecutively stented lesions and was successfully obtained for 94 (78%).

RESULTS

The mean graft age (+/- SD) was 8.7 +/- 4 years. Stent placement was successful in 197 (98.5%) of 200 lesions, reducing the mean diameter stenosis from 74 +/- 14% to 1 +/- 15%. In 164 procedures, there was one in-hospital death (0.6%), no emergency bypass operations and no Q wave myocardial infarctions. There was one acute stent thrombosis (0.6%) but no subacute thromboses. Vascular repair was required after 14 procedures (8.5%), with transfusion in 23 additional cases (14%). Angiographic restenosis (diameter stenosis > or = 50%) at 3- to 6-month follow-up was 17% (95% confidence interval 9% to 25%). By Kaplan-Meier estimates, however, the 2-year second revascularization rate was 49%, reflecting the predominant revascularization performed to treat progressive disease at other sites because failure at the stented site occurred in only 22% of lesions.

CONCLUSIONS

Stenting resulted in excellent immediate and long-term angiographic results in this group of focally diseased, older saphenous vein grafts. Despite the high immediate success and very low (17%) angiographic restenosis rate at 6 months, approximately one half of these patients required further revascularization in the following 2 years, mainly because of disease progression at other sites.

Balloon postdilation can safely improve the results of successful (but suboptimal) directional coronary atherectomy

This study investigates whether adjunctive balloon angioplasty can be safely used to improve acute results in cases where directional coronary atherectomy alone has provided a successful (but suboptimal) outcome. Between October 1, 1990, and October 1, 1992, directional coronary atherectomy was performed successfully in 198 of 228 lesions. Individual operators believed that most acute results were satisfactory after atherectomy alone (group I, n = 115) with a minimal lumen diameter that increased from 0.82 +/- 0.45 to 3.21 +/- 0.65 mm after atherectomy, for an acute gain in lumen diameter of 2.39 +/- 0.73 mm and a residual stenosis of 6 +/- 13%. In 42% of lesions (group II, n = 83), however, results were considered suboptimal after atherectomy alone, with a minimal lumen diameter that increased from 0.85 +/- 0.45 to 2.83 +/- 0.64 mm, a smaller acute gain of 1.96 +/- 0.72 mm, and a mean residual stenosis of 17 +/- 14% (although all residual stenoses were < 50%, 19% had a residual stenosis > 30%). Adjunctive balloon angioplasty in these group II lesions provided an additional gain of 0.34 +/- 0.38 mm, bringing the total acute gain for group II lesions to 2.32 +/- 0.78 mm and the residual stenosis to 9 +/- 13%, similar to that of group I patients who underwent atherectomy alone. This strategy resulted in a 7 +/- 13% overall residual stenosis for the study population, with no higher incidence of periprocedural complications or adverse late clinical outcomes in group II patients.(ABSTRACT TRUNCATED AT 250 WORDS)