Larry S. Dean

Intracoronary stenting for acute and threatened closure complicating percutaneous transluminal coronary angioplasty.

BackgroundAcute closure remains a significant limitation of percutaneous transluminal coronary angioplasty (PTCA) and underlies the majority of ischemic complications. This study details the clinical and angiographic characteristics of a series of patients receiving an intracoronary stent device to manage acute and threatened closure and presents the early clinical results. Methods and ResultsFrom October 1989 through June 1991, 115 patients undergoing PTCA received intracoronary stents to treat acute or threatened closure in 119 vessels. Sixty-three percent had multivessel coronary disease, 33 (29%) had undergone prior coronary artery bypass grafting (CABG), and 52 (45%) had had previous PTCA. Using the American College of Cardiology/American Heart Association (ACC/AHA) classification, 15% of lesions were class A, 55% were class B, and 30% were class C. Eight patients were referred with severe coronary dissection and unstable angina after PTCA at other institutions. Acute closure was defined as occlusion of the vessel with TIMI (Thrombolysis in Myocardial Infarction) 0 or 1 flow immediately before stent placement. Threatened closure required two or more of the following criteria: 1) a residual stenosis greater than 50%, 2) TIMI grade 2 flow, 3) angiographic dissection comprising extraluminal dye extravasation and/or a length of greater than 15 mm, 4) evidence of clinical ischemia (either typical angina or ECG changes). Twelve vessels (10%) met the criteria for acute closure, and 87 vessels (73%) satisfied the criteria for threatened closure. Twenty vessels (17%) failed to meet two criteria. Stenting produced optimal angiographic results in 111 vessels (93%), with mean diameter stenosis (±1 SD) reduced from 83±12% before to 18±29% after stenting. Overall, in-hospital mortality was 1.7% and CABG was required in 4.2%; Q wave myocardial infarction (MI) occurred in 7% and non-Q wave MI in 91%. Stent thrombosis occurred in nine patients (7.6%). For the 108 patients who presented to the catheterization laboratory without evolving MI, Q wave MI occurred in 4% and non-Q wave MI occurred in 7%. Angiographic follow-up has been performed in 81 eligible patients (76%), and 34 patients (41%) had a lesion of .50%. ConclusionsThis stent may be a useful adjunct to balloon dilatation in acute or threatened closure. Randomized studies comparing this stent with alternative technologies are required.

Predictors of Stroke Complicating Carotid Artery Stenting

BACKGROUND The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection. METHODS AND RESULTS We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes. CONCLUSIONS During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Left ventricular volume measurement using cardiac axis nuclear magnetic resonance imaging. Validation by calibrated ventricular angiography.

Proton nuclear magnetic resonance (NMR) imaging has the potential to serially assess left ventricular (LV) volumes with optimal accuracy because it is a high-resolution, three-dimensional, noninvasive modality. Previous NMR studies to assess LV volumes have been suboptimal, as they have used either planes aligned with the axes of the body, which are compromised by partial volume effects, or spin-echo techniques that have been time-consuming to acquire and analyze. Accordingly, for LV volume measurement, we developed a gradient-echo (cine) NMR strategy that uses two orthogonal planes intersecting along the intrinsic long axis of the heart (two-chamber and four-chamber). This approach was validated against calibrated contrast biplane LV cineangiography (CATH) and also compared with a previously reported short-axis spin-echo NMR method. Twenty-one patients underwent CATH and NMR (long-axis, n = 21; short-axis, n = 14) within a 3-day interval. Although both long- and short-axis NMR LV volumes and ejection fractions correlated well with CATH (r greater than 0.90, p less than 0.001 in all), end-diastolic volumes by both long-axis (161 +/- 85 ml) and short-axis (151 +/- 81 ml) NMR were systematically less than those by CATH (182 +/- 85 ml) (p less than 0.05). Consequently, ejection fractions by long-axis (48 +/- 17%) and short-axis (49 +/- 17%) NMR consistently underestimated those by CATH (54 +/- 16%, p less than 0.05). End-systolic volumes by long-axis (94 +/- 71 ml) and short-axis (87 +/- 72 ml) NMR were not significantly different from those by CATH (92 +/- 69 ml). Both NMR techniques had low intraobserver and interobserver variation (less than 11%); however, short-axis spin-echo NMR involved longer acquisition/reconstruction (35 versus 18 minutes) and analysis (25 versus 10 minutes) times. We conclude that both short-axis spin-echo and long-axis gradient-echo NMR approaches reliably estimate LV volumes. Currently, the long-axis strategy appears more practical for clinical use because the scan and analysis times are relatively short.

Percutaneous transmyocardial laser revascularisation for severe angina: the PACIFIC randomised trial

BACKGROUND Percutaneous transmyocardial laser revascularisation (PTMR) is a proposed catheter-based therapy for refractory angina pectoris when bypass surgery or angioplasty is not possible. We undertook a randomised trial to assess the safety and efficacy of this technique. METHODS 221 patients with reversible ischaemia of Canadian Cardiovascular Society angina class III (61%) or IV (39%) and incomplete response to other therapies were recruited from 13 centres. Patients were randomly assigned PTMR with a holmium:YAG laser plus continued medical treatment (n=110) or continued medical treatment only (n=111). The primary endpoint was the exercise tolerance at 12 months. Analyses were by intention to treat. FINDINGS 11 patients died and 19 withdrew; 92 PTMR-group and 99 medical-treatment-group patients completed the study. Exercise tolerance at 12 months had increased by a median of 89.0 s (IQR -15 to 183) with PTMR compared with 12.5 s (-67 to 125) with medical treatment only (p=0.008). On masked assessment, angina class was II or lower in 34.1% of PTMR patients compared with 13.0% of those medically treated. All indices of the Seattle angina questionnaire improved more with PTMR than with medical care only. By 12 months there had been eight deaths in the PTMR group and three in the medical treatment group, with similar survival in the two groups. INTERPRETATION PTMR was associated with increased exercise tolerance time, low morbidity, lower angina scores assessed by masked reviewers, and improved quality of life. Although there is controversy about the mechanism of action, and the contribution of the placebo effect cannot be quantified, this unmasked study suggests that this palliative procedure provides some clinical benefits in the defined population of patients.

Four-year follow-up of patients undergoing percutaneous balloon mitral commissurotomy A report from then national heart, lung, and blood institute balloon valvuloplasty registry

OBJECTIVES This study reports the long-term outcome of patients undergoing percutaneous balloon mitral commissurotomy who were enrolled in the National Heart, Lung, and Blood Institute (NHLBI) Balloon Valvuloplasty Registry. BACKGROUND The NHLBI established the multicenter Balloon Valvuloplasty Registry in November 1987 to assess both short- and long-term safety and efficiency of percutaneous balloon mitral commissurotomy. METHODS Between November 1987 and October 1989, 736 patients > or = 18 years old underwent percutaneous balloon mitral commissurotomy at 23 registry sites in North America. The maximal follow-up period was 5.2 years. RESULTS The actuarial survival rate was 93 +/- 1% (mean +/- SD), 90 +/- 1.2%, 87 +/- 1.4% and 84 +/- 1.6% at 1, 2, 3 and 4 years, respectively. Eighty percent of the patients were alive and free of mitral surgery or repeat balloon mitral commissurotomy at 1 year. The event-free survival rate was 80 +/- 1.5% at 1 year, 71 +/- 1.7% at 2 years, 66 +/- 1.8% at 3 years and 60 +/- 2.0% at 4 years. Important univariable predictors of actuarial mortality at 4 years included age > 70 years (51% survival), New York Heart Association functional class IV (41% survival) and baseline echocardiographic score > 12 (24% survival). Multivariable predictors of mortality included functional class IV, higher echocardiographic score and higher postprocedural pulmonary artery systolic and left ventricular end-diastolic pressures (p < 0.01). CONCLUSIONS Percutaneous balloon mitral commissurotomy has a favorable effect on the hemodynamic variables of mitral stenosis, and long-term follow-up data suggest that it is a viable alternative with respect to surgical commissurotomy in selected patients.

Trends in Coronary Revascularization in the United States From 2001 to 2009 Recent Declines in Percutaneous Coronary Intervention Volumes

Background— There is speculation that the volume of percutaneous coronary interventions (PCIs) has been decreasing over the past several years. Published studies of PCI volume have evaluated regional or hospital trends, but few have captured national data. This study describes the use of coronary angiography and revascularization methods in Medicare patients from 2001 to 2009. Methods and Results— This retrospective study used data from the Centers for Medicare & Medicaid Services from 2001 to 2009. The annual number of coronary angiograms, PCI, intravascular ultrasound, fractional flow reserve, and coronary artery bypass graft (CABG) surgery procedures were determined from billing data and adjusted for the number of Medicare recipients. From 2001 to 2009, the average year-to-year increase for PCI was 1.3% per 1000 beneficiaries, whereas the mean annual decrease for CABG surgery was 5%. However, the increase in PCI volume occurred primarily from 2001 to 2004, as there was a mean annual rate of decline of 2.5% from 2004 to 2009; similar trends were seen with diagnostic angiography. The use of intravascular ultrasound and fractional flow reserve steadily increased over time. Conclusions— This study confirms recent speculation that PCI volume has begun to decrease. Although rates of CABG have waned for several decades, all forms of coronary revascularization have been declining since 2004.

Randomized Comparison of GR-II Stent and Palmaz-Schatz Stent for Elective Treatment of Coronary Stenoses

BackgroundThis prospective multicenter randomized clinical trial was designed to evaluate the long-term angiographic and clinical outcomes of elective treatment with the GR-II stent compared with the Palmaz-Schatz (PS) stent in patients with coronary stenoses. Methods and ResultsSeven hundred fifty-five patients with myocardial ischemia and de novo native coronary stenoses in 3- to 4-mm vessels were randomly assigned to the PS (375 patients) or the GR-II stent (380 patients). The primary end point was 12-month target lesion revascularization (TLR)-free survival. Angiography was performed at baseline and at follow-up in the first 300 consecutive patients to assess the frequency of angiographic restenosis. Procedure success was 98.5% for the GR-II stent and 99.4% for the PS stent (P =0.19). At 30 days, patients assigned to the GR-II stent had a higher stent thrombosis rate (3.9% versus 0.3% for PS stent, P <0.001) and TLR rate (3.9% versus 0.5% for PS stent, P <0.001). The GR-II group had a higher follow-up restenosis frequency (47.3% versus 20.6% for the PS group, P <0.001) and a lower 12-month TLR-free survival rate (71.7% versus 83.9% for the PS group, P <0.001). Multivariate logistic regression analysis identified a smaller final stent minimal lumen diameter (odds ratio [OR] 2.49, 95% CI 1.56 to 3.98;P <0.001), diabetes mellitus (OR 2.14, 95% CI 1.42 to 3.22;P <0.001), and use of the GR-II stent (OR 1.78, 95% CI 1.20 to 2.64;P <0.01) as independent determinants of 12-month TLR. ConclusionsOn the basis of these long-term follow-up data, we conclude that use of the GR-II stent should be limited to the acute treatment of abrupt or threatened closure after failed conventional balloon angioplasty procedures.

Outcome probabilities and life history after surgical mitral commissurotomy : implications for balloon commissurotomy

From 1967 to 1988, 339 patients with mitral stenosis underwent surgical commissurotomy, 103 with a closed and 236 with an open technique. The 1 month and 1, 5, 10 and 20 year overall survival rate was 99.7%, 99%, 95%, 87% and 59%, respectively, and the technique (open versus closed) was not a risk factor. Technique was also not a risk factor for a second mitral commissurotomy, subsequent mitral valve replacement, thromboembolism or poor functional status. Risk factors were older age at commissurotomy, black race, higher pulmonary vascular resistance, mitral leaflet calcification, left ventricular enlargement and postcommissurotomy mitral incompetence. The closed technique was a risk factor for mitral incompetence immediately after commissurotomy, but important incompetence developed in only 2 of the 103 patients undergoing closed commissurotomy. Mitral valve replacement was not required within 10 years in 78% of patients and within 20 years in 47%. Despite some increased prevalence of postcommissurotomy mitral incompetence and particularly in view of the considerable long-term likelihood of mitral valve replacement, initial therapy for most patients with mitral stenosis should probably be surgical closed (or percutaneous balloon) mitral commissurotomy. The equations developed in the present study can be used to predict and compare outcome probability after percutaneous balloon commissurotomy with that after surgical commissurotomy and to compare these with outcome probability after mitral valve replacement.

Expert Consensus Statement on the Use of Fractional Flow Reserve, Intravascular Ultrasound, and Optical Coherence Tomography: A Consensus Statement of the Society of Cardiovascular Angiography and Interventions

The rationale for use of intracoronary physiology assessment and imaging arises from the limitations of coronary angiography, the traditional method for determining the severity of coronary stenoses. The visual assessment of percent diameter reduction has significant interobserver variability [1–3], even among experienced angiographers [4]. Computer-assisted quantitative coronary angiography only marginally improves diagnostic accuracy and its estimate of functional significance [5]. Fractional flow reserve (FFR) is used to determine the functional significance of a coronary stenosis [6]. Intravascular ultrasound (IVUS) offers excellent visualization of intraluminal and transmural coronary anatomy. Optical coherence tomography (OCT) further improves vascular visualization. There is now persuasive evidence regarding intracoronary diagnostic lesion assessments using physiology and anatomy. These adjunctive diagnostic procedures may influence the decision for coronary revascularization, guide the performance of percutaneous coronary interventions (PCI), and optimize procedural outcomes. There are substantial long-term outcome data showing benefit associated with FFR-guided decision-making. However, these techniques are underutilized in contemporary practice: the rates of use of IVUS and FFR during PCI for intermediate coronary stenoses (40–70% diameter stenosis) are 20.3% and 6.1% respectively [7]. In 2011, the ACCF/AHA/SCAI PCI guidelines [8] assigned levels of evidence for the use of these modalities in various clinical situations (Table T1 I). The purpose of this consensus statement is to review recent studies, to develop a consensus of how these

Predictors of Thrombotic Complications After Placement of the Flexible Coil Stent

The balloon-expandable, stainless steel, flexible coil stent is a useful device for managing acute or threatened closure after percutaneous transluminal coronary angioplasty.1–5 Use of the device is associated with thrombosis of the stented vessel in a small but important group of patients.3,6–10 The clinical, angiographic, and procedural factors associated with stent thrombosis with this device are still unknown. The objective of this study was to define predictors of stent thrombosis occurring within the ftrst month after stenting with this device.