Coronary dissection and total coronary occlusion associated with percutaneous transluminal coronary angioplasty: significance of initial angiographic morphology of coronary stenoses

Validation of the Ability of SYNTAX and Clinical SYNTAX Scores to Predict Adverse Cardiovascular Events After Stent Implantation: A Systematic Review and Meta-Analysis

To compare the predicative ability of SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) and clinical SYNTAX scores for major adverse cardiac events (MACEs) after stent implantation in patients with coronary artery disease (CAD). Studies were identified by electronic and manual searches. Twenty-six studies were included in the meta-analysis. The pooled C-statistics of SYNTAX score for 1- and 5-year all-cause mortality (ACM) were 0.65 (95% confidence interval [CI]: 0.61-0.68) and 0.62 (95% CI: 0.59-0.65), respectively, with weak heterogeneity. The 1- and 5-year ACM pooled C-statistics for clinical SYNTAX scores were significantly higher at 0.77 and 0.71, respectively (Ps < .05). Both scoring systems predicted 1- and 5-year MACE equally well. The pooled risk ratio of the SYNTAX score for predicting 1-year ACM per unit was 1.04 (95% CI: 1.03-1.05). Calibration analysis indicated SYNTAX scores overestimated the risk of major adverse cardiac and cerebrovascular events in each risk stratum. The SYNTAX score demonstrated minimal discrimination in predicting 1- or 5-year adverse cardiovascular events after percutaneous coronary intervention in patients with CAD. The clinical SYNTAX score could further improve the predictive capability for ACM but not MACE.

The SYNTAX Score Can Predict Major Adverse Cardiac Events Following Percutaneous Coronary Intervention

OBJECTIVES

The SYNTAX score is a grading system that evaluates the complexity and prognosis of patients undergoing percutaneous coronary intervention (PCI). We investigated the association between the incidence of major adverse cardiac events (MACE) following PCI and the SYNTAX score in patients with three-vessel disease.

METHODS

We consecutively enrolled 381 patients with three-vessel disease undergoing PCI and stenting. The SYNTAX score was divided into tertiles as low (≤16), intermediate (16-22) and high (>22). The endpoint was the incidence of MACE defined as cardiac death, in-hospital mortality, nonfatal myocardial infarction (MI), or target vessel revascularization. Then, the incidence of MACE was compared among the SYNTAX score tertile groups.

RESULTS

The median follow-up was 14 months, and the rate of MACE was 12.6%. The rates of MACE were 7.5%, 9.9%, and 21.6% in patients with low, intermediate, and high SYNTAX score tertiles, respectively. Higher SYNTAX scores significantly predicted a higher risk of MACE (hazard ratio = 2.36; P = 0.02) even after adjustment for potential confounders. The main predictors of MACE were SYNTAX score, advanced age, hyperlipidemia, presentation as recent ST-elevation MI, number of total lesions, and history of renal failure.

CONCLUSION

The SYNTAX score could predict major cardiac outcomes following PCI in patients with three-vessel disease.

Predictive accuracy of SYNTAX score for predicting long-term outcomes of unprotected left main coronary artery revascularization

The American College of Cardiology/American Heart Association recently updated recommendations for percutaneous coronary intervention (PCI) of unprotected left main coronary artery (ULMCA) disease from class III to II(b) according to the results of the SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery (SYNTAX) trial. The SYNTAX score is an angiographic tool using solely the coronary anatomy. We studied the effect of co-morbidities (Parsonnet's score) on the ability of the SYNTAX score to predict long-term outcomes in patients with ULMCA disease treated by revascularization. A total of 328 patients underwent revascularization of ULMCA from April 2003 to February 2007. Of the 328 patients, 120 underwent PCI (median follow-up 973 days) and 208 underwent coronary artery bypass grafting (CABG) (median follow-up 1,298 days). The ability of the SYNTAX score to predict outcomes was assessed using the Cox proportional hazards model. The outcomes between the PCI and CABG groups were compared by propensity analysis. The median SYNTAX score was 26 in the PCI and 28 in the CABG group (p = 0.5). In the PCI group, greater quartiles were associated with worse survival (62.1% at SYNTAX score of ≥36 vs 82.4% at SYNTAX score of <36, p = 0.03) and all-cause mortality, myocardial infarction, cerebrovascular events, and target vessel revascularization-free (MACCE) survival (47.7%, SYNTAX score ≥20 vs 76.6%, SYNTAX score <20, p = 0.02). Using the Parsonnet score as a covariate, the SYNTAX score continued to be an independent predictor of MACCE and demonstrated a trend toward predicting mortality in the PCI group. In contrast, the SYNTAX score did not predict the outcomes for the CABG group. No difference was found in mortality between the PCI and CABG groups for ULMCA disease, regardless of coronary complexity; although greater SYNTAX scores were associated with increased MACCE rates with PCI compared to CABG. Both the coronary anatomy (SYNTAX score) and co-morbidities (Parsonnet's score) predicted long-term outcomes for PCI of ULMCA disease. In contrast, the SYNTAX score did not predict the outcomes after CABG. In conclusion, the ideal scoring system to guide an appropriate revascularization decision for ULMCA disease should take into account both the coronary anatomy and the co-morbidities.

Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial

OBJECTIVES

We aimed to assess the predictive value of the SYNTAX score (SXscore) for major adverse cardiac events in the all-comers population of the LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial.

BACKGROUND

The SXscore has been shown to be an effective predictor of clinical outcomes in patients with multivessel disease undergoing percutaneous coronary intervention.

METHODS

The SXscore was prospectively collected in 1,397 of the 1,707 patients enrolled in the LEADERS trial (patients after surgical revascularization were excluded). Post hoc analysis was performed by stratifying clinical outcomes at 1-year follow-up, according to 1 of 3 SXscore tertiles.

RESULTS

The 1,397 patients were divided into tertiles based on the SXscore in the following fashion: SXscore<or=8 (SXlow) (n=464), SXscore>8 and <or=16 (SXmid) (n=472), and SXscore>16 (SXhigh) (n=461). At 1-year follow-up, there was a significantly lower number of patients with major cardiac event-free survival in the highest tertile of SXscore (SXlow=92.2%, SXmid=91.1%, and SXhigh=84.6%; p<0.001). Death occurred in 1.5% of SXlow patients, 2.1% of SXmid patients, and 5.6% of SXhigh patients (hazard ratio [HR]: 1.97, 95% confidence interval [CI]: 1.29 to 3.01; p=0.002). The myocardial infarction rate tended to be higher in the SXhigh group. Target vessel revascularization was 11.3% in the SXhigh group compared with 6.3% and 7.8% in the SXlow and SXmid groups, respectively (HR: 1.38, 95% CI: 1.1 to 1.75; p=0.006). Composite of cardiac death, myocardial infarction, and clinically indicated target vessel revascularization was 7.8%, 8.9%, and 15.4% in the SXlow, SXmid, and SXhigh groups, respectively (HR: 1.47, 95% CI: 1.19 to 1.81; p<0.001).

CONCLUSIONS

The SXscore, when applied to an all-comers patient population treated with drug-eluting stents, may allow prospective risk stratification of patients undergoing percutaneous coronary intervention. (LEADERS Trial Limus Eluted From A Durable Versus ERodable Stent Coating; NCT00389220).

Coronary artery stents: Part I. Evolution of percutaneous coronary intervention

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

Cyphering the complexity of coronary artery disease using the syntax score to predict clinical outcome in patients with three-vessel lumen obstruction undergoing percutaneous coronary intervention

The Syntax score (SXscore) was recently developed as a comprehensive angiographic scoring system aiming to assist in patient selection and risk stratification of patients with extensive coronary artery disease undergoing contemporary revascularization. A validation of this angiographic classification scheme is lacking. We assessed its predictive value in patients who underwent percutaneous intervention (PCI) for 3-vessel disease and explored its performance in comparison with the modified lesion classification system of the American Heart Association/American College of Cardiology. The SXscore, applied to 1,292 lesions in 306 patients who underwent PCI for 3-vessel disease in the Arterial Revascularization Therapies Study Part II, was 4 to 54.5, and after a median of 370 days (range 274 to 400) predicted the rate of major adverse cardiac and cerebrovascular events (hazard ratio 1.08/U increase, 95% confidence interval 1.05 to 1.11, p <0.0001), with patients in the highest SXscore tertile having a significantly higher event rate (27.9%) than patients in the lowest tertile (8.7%, hazard ratio 3.5, 95% confidence interval 1.7 to 7.4, p = 0.001). By multivariable analyses, SXscore independently predicted outcome with an almost fourfold adjusted increase in the risk of major adverse cardiac and cerebrovascular events in patients with high versus low values based on the discrimination level provided by classification and regression tree analysis. Compared with the modified lesion classification scheme of the American Heart Association/American College of Cardiology, SXscore showed a greater discrimination ability (c-index 0.58 +/- 0.08 vs 0.67 +/- 0.08, respectively, p <0.001) and a better goodness of fit with the Hosmer-Lemeshow statistic. In conclusion, the SXscore is a promising tool to risk stratify outcome in patients with extensive coronary artery disease undergoing contemporary PCI.

Coronary artery "pseudothrombus" due to collateral flow artifact distal to left circumflex coronary stenosis

Since the complexity, morbidity, and costs of coronary interventions are increased when coronary thrombus is present, identification of the cause of an angiographic filling defect is potentially important. We present a case report and review our experience with a flow artifact that mimicked thrombus ("pseudothrombus") in the setting of a severe proximal stenosis in the left circumflex coronary artery.

Clinical, angiographic, and procedural correlates of abrupt vascular closure during coronary intervention: a 10-year experience at Mayo Clinic

A large matched-cohort study was carried out to determine correlates of in-hospital abrupt vascular closure (AC). Univariate analysis identified current cigarette smoking (P = 0.021), myocardial infarction within 24 hr prior to procedure (P = 0.0035), emergency procedure (P = 0.02), lesion thrombus (P = 0.0001), and lesion angulation (P = 0.021) as significant clinical and angiographic variables. Relative to balloon angioplasty (PTCA), use of atherectomy (P = 0.015) and laser devices (P = 0.018) but not elective stent placement (P = 0.97) were associated with increased risk of AC. In the multivariate model, current cigarette smoking (P = 0.0474), lesion thrombus (P = 0.0001), lesion angulation (P = 0.0124), use of atherectomy devices (P = 0.001), and laser devices (P = 0.0037) remained as significant correlates of increased AC events. In conclusion, the risk of AC appears associated primarily with lesion characteristics and use of nonballoon devices other than stents. Elective stent placement did not appear to reduce AC risk over conventional PTCA; the small number of patients studied may have prevented any benefit from being observed.

[Clinical follow-up 6 months after ambulatory/partial inpatient after-care rehabilitation. Further results of the Cologne model of ambulatory cardiac phase II rehabilitation]

Three hundred and thirty patients with coronary artery disease (CAD) (288 men, 42 women, age of 55.5 +/- 10.0 years) participated in a 4-week ambulatory cardiac rehabilitation program (ACR) (Table 1). The cardiovascular indication for ACR was in 229 cases a myocardial infarction. In 101 patients a CAD with invasive revascularization but without a history of MI was present. In 92 patients with myocardial infarction additionally an invasive revascularization was performed. Eighty-three patients were included after a CABG-procedure (Tables 2 to 5). Six months after the ACR 290 (87.9%) patients presented for clinical reevaluation. In 235 (81.0%) of the 290 examined patients the cardiovascular diagnosis was unaltered. In the first 6 months after ACR in 76 (26.2%) patients a coronarography was performed, in 44 patients a restenosis was diagnosed. In 36 patients an additional invasive procedure (in 28 patients a PTCA, in 5 patients with additional stent-implantation, in 1 case with rotablation, in 8 patients CABG) was performed. In 1 patients a pace-maker was implanted. Since the ACR 1 patient experienced a myocardial infarction and 2 a recurrent myocardial infarction. In 1 patient myocardial fibrillation occurred. Totally, 70 patients (24.1%) required stationary-hospital treatment during the first 6 months after ACR (Table 6). In 11 cases an acute admission to hospital treatment because of cardiovascular reasons was documented. The majority of the hospital admission was elective, because of diagnostic or therapeutic procedures. In 6 patients a CABG-surgery was performed. In approximately 80% of the patients the cardiovascular status was stable during the first 6 months after ACR. Though 24.1% of the patients required stationary hospital treatment, the majority of the admissions was elective of interest, there was a high rate of hospital admissions in the PTCA-group in combination with recoronarographies and revascularization because of early reocclusion.

Abrupt (< 1 day), acute (< 1 week), and early (< 1 month) vessel closure at the angioplasty site. Morphologic observations and causes of closure in 130 necropsy patients undergoing coronary angioplasty

While abundant clinical and angiographic data are available regarding features of acute or abrupt closure at the site of balloon angioplasty, little morphologic information is available. This study discusses morphologic-histologic causes for acute closure after angioplasty in 130 necropsy patients. Intimal-medial flaps, elastic recoil, and primary thrombosis were the three leading morphologic causes for closure. Data were subdivided into time categories: abrupt (< 1 day), acute (< 1 week), and early (< 1 month). Intimal-medial flaps remained the most common cause for angioplasty closure despite time from angioplasty to documented occlusion. Morphologic recognition of types and frequencies of angioplasty closure are discussed, and specific mechanical, pharmacologic, or combined treatments are reviewed.

In-hospital outcome of percutaneous transluminal coronary angioplasty for long lesions and diffuse coronary artery disease

We performed coronary angioplasty on 151 long or diffuse lesions (120 long and 31 diffuse) in 141 patients (86% male, mean age 50 +/- 9 years). Long lesions were defined as lesions 11-20 mm in length and diffuse lesions as lesions longer than 20 mm, or three or more lesions in the same vessel. One or more adverse morphologic features were present in 131 (93%) lesions. Long balloons were used in 44%, significantly more often for diffuse disease (long lesions 39% and diffuse disease 64%; P = 0.004). Newer devices including the rotational atherectomy device (9 lesions), stents and perfusion balloons were employed in 18 (12%) lesions, more often for diffuse lesions (long lesions 8% vs. diffuse lesions 26%; P = 0.017). Lesion severity was comparable in the two groups (long lesions: 88 +/- 7%; diffuse lesions: 88 +/- 8%), but diffuse lesions were associated with significantly higher residual stenosis (long lesions: 6 +/- 8%; diffuse lesions: 12 +/- 13%, P = 0.01). Major complications occurred in five (3.5%) patients, including one death (0.7% mortality). The angiographic and clinical success rates for all patients were 99% and 96%, respectively, and were comparable for long and diffuse lesions. Judicious case selection and the use of long balloons and newer interventional devices permit coronary angioplasty for long lesions and diffuse disease with excellent success and a low risk of complications. Diffuse lesions are associated with more frequent use of long balloons and newer devices, especially rotational atherectomy and slightly higher residual stenosis as compared to long lesions.

Angioscopic versus angiographic detection of thrombus during coronary interventional procedures

The purpose of this study was to compare angiography and angioscopy for the detection of thrombus during coronary interventional procedures. The diagnosis of coronary thrombus has important clinical implications. Angioscopy can directly visualize the coronary luminal surface and may be more accurate than angiography in the diagnosis of thrombus. Angiography and angioscopy were sequentially performed in 75 patients undergoing a variety of interventional cardiology procedures during 117 distinct procedural time points. The angiographic presence of thrombus was defined as a noncalcified filling defect outlined on at least 3 sides by contrast media. The angioscopic presence of thrombus was defined as red material protruding into the lumen (intraluminal thrombus) or adherent to the luminal wall (mural thrombus) that persisted despite flushing. Thrombus was detected on 14 occasions (12.0%) by angiography compared with 48 (41.0%) by angioscopy (p < 0.05). In 4 of the 14 episodes (28.6%) of angiographic filling defects, angioscopy found no evidence of thrombus and provided an alternative explanation for the angiographic filling defect. When angioscopy was used as a reference standard, the sensitivity of thrombus detection by angiography was 20.8%, with a specificity of 94.2% and a predictive value of 71.4%. The sensitivity of angiography for the detection of intraluminal (protruding into the lumen) thrombus was 100% compared with only 10% for mural (adherent to the luminal wall) thrombus (p < 0.05). Angioscopy was significantly more accurate than angiography for detecting coronary thrombus and may be considered an improved reference standard for this diagnosis.

Clinical and lesion morphologic determinants of coronary angioplasty success and complications: current experience

OBJECTIVES

This study evaluated the validity of the American College of Cardiology/American Heart Association ABC lesion classification scheme and its modifications.

BACKGROUND

With the continued refinement in angioplasty technique and equipment evolution, the lesion morphologic determinants of immediate angioplasty outcome have changed significantly. Hence, the validity of the classification scheme has been questioned.

METHODS

We assessed the lesion morphologic determinants of immediate angioplasty outcome in 729 consecutive patients who underwent coronary angioplasty of 994 vessels and 1,248 lesions.

RESULTS

Angioplasty success was achieved in 91% of lesions, and abrupt closure occurred in 3%. Success was achieved in 96%, 93% and 80% of type A, B and C lesions, respectively (A vs. B, p = NS; B vs. C, p < 0.001; A vs. C, p < 0.001; A vs. B1, p = NS; A vs. B2, p = 0.03; B1 vs. B2, p = 0.02; B2 vs. C, p < 0.001; C1 vs. C2, p = NS). Abrupt closure occurred in 2.1%, 2.6% and 5% of type A, B and C lesions, respectively (A vs. B, B vs. C, A vs. C and A vs. B1, all p = NS; B1 vs. B2, p = 0.01; B2 vs. C1, p = NS; C1 vs. C2, p = 0.04). Type B characteristics had a success rate ranging from 74% to 95% and an abrupt closure rate ranging from 2.2% to 14%. Type C characteristics had a success rate ranging from 57% to 88% and an abrupt closure rate ranging from 0% to 16%. Longer lesions, calcified lesions, diameter stenosis of 80% to 99% and presence of thrombus were predictive of a lower success rate. Longer lesions, angulated lesions, diameter stenosis of 80% to 99% and calcified lesions were predictive of an abrupt closure.

CONCLUSIONS

The previously proposed classification schemes are outdated and need to be changed for application in current angioplasty practice. Analyzing specific lesion morphologic characteristics rather than applying a simple lesion classification score when evaluating angioplasty outcome may be more useful because it provides a more precise profile of the lesion and allows better patient stratification and selection.

Coronary stenting with angioscopic guidance

Coronary angioscopy can directly visualize luminal morphology and stent architecture. This new technology may provide insights into the stent mechanism of action and help guide stent procedures. Visualization of the target vessel segment with a 4.5Fr angioscope was attempted before and/or after Palmaz-Schatz coronary stent implantation in 50 patients. The target vessel segment was successfully visualized in 48 patients (96%). In 24 patients, angioscopy was performed both after balloon angioplasty and then again after stenting. In 16 of these 24 patients a dissection was documented by angioscopy after balloon angioplasty, and in each patient the dissection was absent after stenting. Angioscopy influenced the clinical management of 18 (37.5%) patients. Clinical decisions directly influenced by angioscopy included intracoronary thrombolytic therapy for thrombus visualized angioscopically, which had been unsuspected by angiography (n = 7), withholding intracoronary thrombolytic therapy for patients with suspected thrombus not confirmed by angioscopy (n = 4), repeat angioplasty in patients in whom plaque was found to be bulging into the lumen at the stent articulation site (n = 4), additional stents placed when angioscopy revealed significant proximal or distal disease (n = 4), or an unsuspected gap between 2 tandem stents (n = 1). Coronary angioscopy safely visualized stented vessel segments in most patients. Angioscopic observations provided insights into the stent mechanism of action and, in some cases, influenced clinical management.

Development of a new technique for reducing pressure pulse generation during 308-nm excimer laser coronary angioplasty

Despite expectations that excimer laser ablation would result in a low incidence of coronary dissection, studies have documented a 15-20% incidence of dissection (including a 4-6% incidence of clinically significant dissection) during excimer interventions. This investigation sought to determine if pressure pulses produced by the exposure of fluid phase media (blood and contrast) to 308-nm excimer radiation might contribute to untoward outcomes. Pressure pulses generated in these media were quantitated to be > 100 atm. In vitro ablation of porcine aorta in the presence of blood or contrast resulted in tissue dissection, while ablation in pure crystalloid did not. Next, a "flush and bathe" technique designed to replace all blood and contrast with crystalloid was applied to a pilot population of 57 consecutive patients. There were no rhythm disturbances or laser-related clinically significant dissections in this group, and the clinical success rate was 95%. In summary, this report quantitates a potential etiology for excimer dissection and suggests that replacement of blood and contrast with crystalloid might improve procedural and clinical success rates.

Predicting the risk of abrupt vessel closure after angioplasty in an individual patient

OBJECTIVES

We proposed to examine the relation between angiographic morphologic characteristics and abrupt closure after coronary angioplasty and to develop an empirically based risk stratification system.

BACKGROUND

Certain lesion morphologic characteristics are associated with higher rates of abrupt closure after coronary angioplasty. Previous approaches have been limited by relatively small sample sizes and an inability to combine multiple characteristics to predict risk in an individual patient.

METHODS

Lesion morphology was determined for 779 lesions in 658 patients undergoing an elective first angioplasty. Abrupt closure occurred in 63 lesions (8.1%). Variables associated with abrupt closure were identified by univariate and stepwise multiple logistic regression analysis, and internal validity was assessed by use of bootstrapping. An empirically based scoring system was developed by assigning different weights to each predictive characteristic and was then validated.

RESULTS

Almost all lesion characteristics previously labeled "adverse" were associated with an increased risk of abrupt closure, but only total occlusion, location at a branch point, increasing lesion length, evidence for thrombus and right coronary artery location were statistically significant independent predictors. Despite the large sample size, the study was underpowered to detect even a 50% increase in risk with many characteristics. Using a scoring system, we assigned each lesion a specific risk of abrupt closure. The distribution of risk was broad, with 20% of patients having < or = 2.5% risk and 25% having > 10% risk. Internal validation techniques revealed that when 10% of patients were randomly eliminated from the sample in multiple iterations, the risk estimates varied, again pointing to the need for a larger sample.

CONCLUSIONS

Empirically based weighting of lesion characteristics could quantify the risk of abrupt closure for individual patients, but a very large sample will be required to understand the interplay of complex lesion characteristics in altering expected outcomes.

Continuous coronary flow velocity monitoring during coronary interventions: velocity trend patterns associated with adverse events

Continuous measurement of blood flow velocity during interventional procedures has the potential to provide an early warning of coronary flow instability, which can lead to abrupt closure or other adverse events before angiography. The magnitude and fluctuations of the average velocity over time (trend) was studied by using a 0.018-inch Doppler-tipped angioplasty guide wire in 32 patients after coronary angiography (n = 20), atherectomy (n = 2), urgent stent (n = 6), urgent vein graft thrombolysis (n = 4), or acute myocardial infarction (n = 2). The patients (mean age 60 +/- 11 years) had postprocedural in-laboratory flow monitoring for a mean of 19 +/- 11 (range 8 to 36) minutes. The coronary artery monitored was the left anterior descending in 13, circumflex in 6, right coronary artery in 9, and saphenous vein graft in 4. Seven patients had flow-related events during continuous flow velocity monitoring before serial angiographic study. These events included coronary vasospasm (abrupt flow acceleration), vasovagal flow cessation, cyclical flow variations resulting from accumulation of intraluminal thrombus, and rapid decline of flow velocity. The last two patterns were associated with abrupt vessel closure during angioplasty. Continuous flow velocity monitoring is easily incorporated into routine interventional procedures and provides an early indication of unstable flow and the potential for abrupt vessel closure and other adverse events.

The impact of balloon material and lesion characteristics on the incidence of angiographic and clinical complications of coronary angioplasty

To assess the importance of balloon material used for percutaneous transluminal coronary angioplasty (PTCA), we compared the complication rates observed with low complaint plastomer (PM 300), intermediately compliant polyethylene (PE 600), and highly compliant polyolefin copolymer (POC) balloons. In a total of 1,650 procedures, one of these balloon materials was used to dilate 2,040 lesions. The dissection rate tended to be slightly lower with the use of more compliant balloon material. The total clinical complication rate (death, emergency coronary surgery, myocardial infarction, need for bail-out stenting or for prolonged heparin treatment, abrupt out-of-laboratory vessel closure) was 8.1%, 7.4%, and 4.2% in the procedures exclusively performed with PM 300 (N = 653), PE 600 (N = 543) and POC (N = 454) balloons, respectively (P = 0.03). In multivariate analysis, the use of less compliant balloon material emerged as an independent correlate of clinical complications (P = 0.007). However, the predictive power of the lesion complexity (B2, C versus A, B1) was four times stronger. In contrast to current concerns, the use of compliant balloon material seems at least as safe as the use of less compliant material.

Discordance in the predictors of mortality vs. those of ischemic complications following transcatheter coronary intervention

Outcomes of percutaneous transluminal coronary angioplasty (PTCA) depend upon the skill of the angioplasty team and on the characteristics of the patient population. Comparisons of outcomes from different laboratories must take into account the latter. A discordance may exist between the baseline predictors of death in hospital following PTCA and those for periprocedural ischemia. Baseline clinical and procedural characteristics of 3,725 patients who underwent PTCA during 1991 and 1992 were compared with complications by multivariate analysis. The age of the patient and the occurrence of an MI within the previous 30 days were the most powerful independent predictors of death. Ischemic complications were not independently associated with these factors. Emergency CABG was associated independently with target lesion complexity and abrupt reclosure, with unstable angina or attempted saphenous vein graft dilatation. Thus, mortality may more directly reflect baseline clinical characteristics than the skill of operators in avoiding ischemic complications.

Microwave balloon angioplasty effectively seals arterial dissections in an atherosclerotic rabbit model

OBJECTIVES

The purpose of this study was to determine the effectiveness of microwave balloon angioplasty in sealing arterial dissections and to characterize the histologic features associated with this intervention.

BACKGROUND

Coronary dissection accompanying balloon dilation is frequently associated with abrupt closure and acute ischemic complications. Effective management of this complication remains an active area of investigation. Because thermal energy is effective in welding separated atherosclerotic plaques, a microwave-based catheter system that provides controlled local heating was utilized in vessels with angioplasty-induced dissections.

METHODS

Iliac artery dissections were induced in ahypercholesterolemic rabbit model. Vessels were randomly assigned to treatment with standard balloon angioplasty (control vessels) or microwave balloon angioplasty using an average temperature of 80 degrees C. The response of the artery was assessed angiographically and histologically.

RESULTS

Angiographic success, defined as a reduction of dissection length by > 50% or the resolution of lumen haziness, was achieved in 63% of microwave-treated vessels and in 16% of control vessels (p < 0.005). Dissection length (mean +/- SD) was reduced 8.0 +/- 4.8 mm in microwave-treated vessels compared with 0.1 +/- 7.9 mm in vessels receiving standard balloon inflations (p < 0.005). Cellular necrosis was more commonly observed in microwave-treated vessels than in control vessels (73% vs. 17%, p < 0.05), but less intraluminal thrombus was seen in vessels exposed to microwave energy (p < 0.05).

CONCLUSIONS

Microwave balloon angioplasty is more effective than routine balloon inflations in sealing arterial dissections in this model and appears to be less thrombogenic in these markedly disrupted vessels.

The clinical utility of angioscopy during intracoronary stent implantation

Angiographic evidence of thrombus may have important implications during coronary stent deployment procedures. The periprocedural presence of thrombus has been shown to increase the risk of subsequent stent thrombosis. Coronary angioscopy is a new technology that may prove more accurate for the detection of coronary thrombus. Angiographic filling defects suspicious for thrombus were observed in 15 (22%) of 64 patients undergoing coronary angioscopy during stent implantation procedures. Angioscopy confirmed the presence of thrombus in 9 (60%) of these 15 patients. Protruding thrombus was found in four cases and only mural thrombus in five. In six cases (40%) thrombus was not visualized and angioscopy provided an alternative explanation for the angiographic filling defect. Bulky atherosclerotic plaque was seen protruding into the lumen in two cases, disection with protruding fronds of tissue was found in three cases and a ruptured venus valve was found in one final case. Thrombolytic therapy was administered in all four cases containing protruding thrombus, in only two of the five cases containing mural thrombus, and in none of the cases where thrombus was not visualized. Angioscopy was more accurate than angiography for the diagnosis of thrombus and allowed more precise tailoring of the intervention to the underlying anatomical substraight. This resulted in an excellent clinical outcome, with no episodes of stent thrombosis and limitation of the risks associated with thrombolytic therapy to only those patients at increased risk of a thrombotic complication.

High-frequency rotational ablation following failed percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) failed in 29 of 1,150 patients (2.5%) after successful passage of the guide wire. The reasons for failure were inability to pass the lesion with a balloon in 28 patients and inability to dilate the lesion in 1 patient. In these patients (15 stenoses and 14 chronic occlusions) rotational ablation was performed. We were able to pass the burr through the lesion in all of them, resulting in a reduction of diameter stenosis from 87 +/- 15 to 51 +/- 18%. Rotational ablation alone was initially successful (stenoses reduction > 20% and residual stenoses < 50%) in 15 of 29 (52%) patients. Additional PTCA was performed in 21 of 29 (72%) patients, in 8 to optimize the initially successful result and in 13 because the outcome was unsatisfactory. After dilatation the diameter stenosis was reduced to 41 +/- 14% immediately after the procedure and to 36 +/- 13% at 24 hr control. Overall success was achieved in 21 of 29 (72%) patients immediately after the procedure and in 26 of 29 (90%) patients at 24 hr control. No acute major complications occurred. We conclude that rotational ablation can be used as a safe and effective alternative when PTCA is not successful.

High frequency rotational ablation: an alternative in treating coronary artery stenoses and occlusions

OBJECTIVE

To prove the safety and effectiveness of high frequency rotational ablation of coronary artery stenoses and occlusion in humans.

SUBJECTS

106 patients with symptoms (91 men, 15 women) who had 67 significant stenoses, mainly types B and C, and 46-chronic occlusions.

MAIN OUTCOME MEASURES

Mean change in diameter stenosis after rotational angioplasty alone and in combination with percutaneous transluminal coronary angioplasty immediately after treatment and 24 hours and six months later; restenosis rates at six months; complication of treatment.

RESULTS

Rotational ablation could not be used in five stenoses and 16 chronic occlusions because of inability to reach or cross the lesion with the Rotablator guide wire. In four cases rotational ablation failed. Initial angiographic and clinical success by rotational ablation was achieved in 40 of the 67 stenoses (60%) and in 18 of the 46 chronic occlusions (39%). Additional balloon angioplasty was performed in 45 patients, increasing the success rates to 79% and 54%, respectively. In the 62 stenoses treated by rotational ablation the angiographic diameter stenoses were reduced from 76% (SD 14%) to 32% (14%) after Rotablator treatment alone and from 75% (11%) to 33% (17%) with additional balloon angioplasty. In the 30 chronic occlusions treated by rotational ablation the angiographic diameter stenoses were reduced to 38% (18%). At six months angiographic restenosis was evident in nine of the 25 (36%) stenoses treated with rotational ablation alone, in seven of the 22 (32%) stenoses treated with rotational and balloon angioplasty, and in 14 of the 24 (58%) chronic occlusions. There were no procedural deaths and two patients (2%) underwent emergency coronary artery bypass grafting. Although no transmural infarction occurred, there were five (6%) non-Q wave infarctions (two embolic side branch occlusions, two subacute occlusions, and one acute occlusion). Clinically insignificant slight increases in creatine kinase activity were seen in five patients (6%). Severe coronary artery spasm unresponsive to medical treatment was provoked in seven cases (8%).

CONCLUSIONS

High frequency rotational ablation is a safe and effective method for treating type B and C coronary artery lesions with results comparable to percutaneous transluminal coronary balloon angioplasty. The combined use of rotational ablation and balloon angioplasty is feasible and is necessary in about half of all procedures, in most cases because the lumen created by the biggest burr is too small.

Pseudodissection of the coronary artery: a variation caused by interventional tools

During PTCA immediate decisions often must be made on the basis of a less than optimum data set. We present a combination of factors which produce an incorrect perception of a coronary artery dissection. This potential must be understood by the interventionalist to avoid misdiagnosis and inappropriate therapeutic maneuvers.

Clinical, angiographic, and procedural determinants of major and minor coronary dissection during angioplasty

Angiographic evidence of coronary dissection after angioplasty is found in 25% to 30% of cases. Although patients are usually asymptomatic, in a small percentage angioplasty-induced coronary dissection results in luminal impairment and ischemic complications. The present study was undertaken to identify factors responsible for a predisposition to coronary dissection after angioplasty and to determine whether major and minor dissections share the same underlying risk factors. Clinical records and angiograms from 363 patients with 489 lesions were retrospectively graded for the presence and severity of dissection and complications. Both major and minor angiographic dissections were noted in 30.3%, and in 8.8% they were major. On multivariate analysis the most significant correlates of any dissection included a balloon-to-artery ratio > 1.1 (p = 0.0001), calcification (p = 0.003), presence of other lesions in the angioplasty vessel (p = 0.018), and lesion length (p = 0.02). However, in a multivariate model there were no variables that could predict whether a dissection would be major or minor. Only the mean total number of inflations was significantly different, but this was likely the result rather than the cause of dissection. Thus a number of variables can predict the occurrence of angiographic coronary dissection after angioplasty. Major dissections constitute a small fraction of the total number but are difficult to predict differentially.

Long-term outcome following successful reopening of abrupt closure after coronary angioplasty

Abrupt closure after coronary angioplasty is often successfully treated by repeat dilation. Long-term follow-up, including 6-month repeat catheterization and 12-month clinical evaluation, was obtained in 1,056 patients treated with acute (n = 335) or elective (n = 721) coronary angioplasty to evaluate the long-term impact of successful reopening of abrupt closure. Abrupt closure occurred in 13.5% of patients and was successfully reopened in 58%. Adverse outcomes including restenosis, death, bypass surgery, myocardial infarction and repeat angioplasty were compared between patients with successfully treated abrupt closure and those with successful procedures (residual diameter stenosis < or = 50%) without abrupt closure. For patients with acute angioplasty, the restenosis rates (> 50% diameter stenosis at follow-up) were 64% for those with successfully treated abrupt closure versus 36% for those with successful procedures without abrupt closure (p < 0.01). In addition, subsequent myocardial infarction (12 vs 3%; p = 0.01) and repeat angioplasty (21 vs 10%; p = 0.03) were more frequent in the group with abrupt closure. For patients with elective angioplasty, restenosis was 43% in those with successfully treated abrupt closure versus 45% in those without abrupt closure (p = NS). Subsequent death and myocardial infarction were more frequent in patients with abrupt closure (death: 12 vs 3% [p < 0.01]; myocardial infarction: 13 vs 3% [p < 0.01]). Long-term adverse events are increased in patients with successfully treated abrupt closure compared to those with successful procedures without abrupt closure.

Usefulness of quantitative and qualitative angiographic lesion morphology, and clinical characteristics in predicting major adverse cardiac events during and after native coronary balloon angioplasty. CARPORT and MERCATOR Study Groups

Major, adverse cardiac events (death, myocardial infarction, bypass surgery and reintervention) occur in 4 to 7% of all patients undergoing coronary balloon angioplasty. Prospectively collected clinical data, and angiographic quantitative and qualitative lesion morphologic assessment and procedural factors were examined to determine whether the occurrence of these events could be predicted. Of 1,442 patients undergoing balloon angioplasty for native primary coronary disease in 2 European multicenter trials, 69 had major, adverse cardiac procedural or in-hospital complications after > or = 1 balloon inflation and were randomly matched with patients who completed an uncomplicated in-hospital course after successful angioplasty. No quantitative angiographic variable was associated with major adverse cardiac events in univariate and multivariate analyses. Univariate analysis showed that major adverse cardiac events were associated with the following preprocedural variables: (1) unstable angina (odds ratio [OR] 3.11; p < 0.0001), (2) type C lesion (OR 2.53; p < 0.004), (3) lesion location at a bend > 45 degrees (OR 2.34; p < 0.004), and (4) stenosis located in the middle segment of the artery dilated (OR 1.88; p < 0.03); and with the following postprocedural variable: angiographically visible dissection (OR 5.39; p < 0.0001). Multivariate logistic analysis was performed to identify variables independently correlated with the occurrence of major adverse cardiac events. The preprocedural multivariate model entered unstable angina (OR 3.77; p < 0.0003), lesions located at a bend > 45 degrees (OR 2.87; p < 0.0005), and stenosis located in the middle portion of the artery dilated (OR 1.95; p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Single site experience with high-speed coronary rotational atherectomy

This report describes a single site experience as part of a multicenter clinical trial with high-speed rotational atherectomy in human coronary arteries. A total of 108 patients with 143 lesions had interventions, were grouped by success or failure, and were analyzed by patient, lesion, and procedural variables. Satisfactory results were achieved in 131 of 143 lesions (92%) and 99 of 108 (92%) patients. Neither patient-related variables (age, gender, diabetes, hypertension, cigarette use, restenosis, previous myocardial infarction, and left ventricular function) nor lesion characteristics (length, ostial or bifurcation location, calcification, lesion classification, and coronary location) were predictive of poor outcome. Tears, acute closure, percentage stenosis after rotational atherectomy and after adjunctive balloon angioplasty were the procedural variables that were statistically associated with outcome by univariate methods. Multivariate analysis isolated postintervention residual stenosis as the only variable that was statistically different between groups. Serious complications included one death in the catheterization laboratory, one Q-wave myocardial infarction, three non-Q myocardial infarctions, and three emergency coronary bypass operations for sustained vessel closure. One patient required emergency surgery for a pacing wire perforation not related to the use of the device. The potential benefits of high-speed rotational atherectomy include increased safety in complex lesions, the ability to address lesions not amenable to balloon techniques, and the possibility of reducing the incidence of restenosis.

Prediction of risk for hemodynamic compromise during percutaneous transluminal coronary angioplasty

The availability of circulatory support devices has increased the importance of accurately identifying patients at risk for hemodynamic compromise during percutaneous transluminal coronary angioplasty (PTCA). Accordingly, prospective evaluation of 3 criteria to predict hemodynamic compromise (defined as a decrease in systolic blood pressure > or = 20 to < 90 mm Hg during balloon inflation) in 157 patients (group A) undergoing PTCA was performed. Left ventricular ejection fraction < 35% had a sensitivity of 13% and a specificity of 95%. Greater than 50% of the myocardium at risk was associated with a sensitivity of 31% and a specificity of 85%. The angiographer's assessment of high risk for hemodynamic compromise had the highest sensitivity of 56% and a specificity of 86%. The clinical and angiographic characteristics of these patients were reviewed to identify risk factors retrospectively. Multivariate analysis of 28 variables identified multivessel disease, diffuse disease, myocardium at risk, and stenosis before PTCA as independent predictors of hemodynamic compromise. With use of this analysis, a 13-point weighted scoring system was created based on the regression of coefficients of the variables. Defining high risk for hemodynamic compromise as a risk score > or = 4, the sensitivity of this criterion in group A patients was 81% and the specificity was 74%. The scoring system was then prospectively applied to 61 consecutive patients (group B) undergoing PTCA. In using a risk score > or = 4 to define high risk, this scoring system had a sensitivity of 92% and a specificity of 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Does the AHA/ACC task force grading system predict outcome in multivessel coronary angioplasty?

To assess the ACC/AHA task force grading system as a predictor of outcome in patients undergoing multivessel percutaneous transluminal coronary angioplasty we analyzed all failures (residual stenosis > 50%, Q-wave myocardial infarction, coronary artery bypass grafting during hospitalization, or death) in 97 patients with 328 stenoses. There were 70 males and 27 females; 60 patients had stable angina, and 37 had unstable angina. The mean number of lesions dilated per patient was 3.4 (range 2-8). The mean preangioplasty percent luminal diameter narrowing was 80 +/- 14%. Thirty-eight stenoses were AHA/ACC classification type A, 192 type B, and 98 type C. One hundred twenty-eight lesions were located in the left anterior descending artery or its distribution, 89 in the left circumflex, 96 in the right coronary artery, and 15 in other vessels. Procedural success (< 50% residual diameter narrowing and no major ischemic complications) was achieved in 266 lesions (81.1%). Major ischemic complications (death, myocardial infarction, or emergency bypass surgery) occurred in 8 patients (8.2%) and in-hospital mortality was 2%. Analysis on a per stenosis basis demonstrated 84% success in type A, 89% in type B, and 64% in type C (p < 0.0001). When type B was divided into type B1 (1 type B characteristic) and type B2 (two or more type B characteristics) the success rate was 90% vs. 88% and the complication rate was 1% vs. 2%, respectively (p = n.s.). Logistic regression analysis showed that the best single predictor of failed angioplasty was total occlusion > 3 months, followed by total occlusion < 3 months and severely angulated (> 90 degrees) segment.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship of anticoagulation level and complications after successful percutaneous transluminal coronary angioplasty

The degree of anticoagulation and its effect on the frequency of abrupt coronary artery closure, coronary ischemia, bleeding complications requiring transfusion, and death were examined in 336 patients after elective percutaneous transluminal coronary angioplasty (PTCA). All patients received a bolus of 10,000 U of heparin at the beginning of the procedure followed by a continuous infusion of 2000 U/hr. At the conclusion of the procedure the infusion was reduced to 1000 U/hr and continued for 18 to 24 hours at which time the heparin infusion was suspended to allow removal of arterial and venous access sheaths. Partial thromboplastin time (PTT) was examined while patients continued to receive the heparin infusion. There was a variable degree of PTT prolongation in response to a standard dose of heparin with a range of 34 seconds to "greater than 150 seconds." Patients were divided into two groups according to the degree of heparin-induced PTT prolongation: group A included 271 patients with PTT greater than or equal to 3 times the control value, and group B comprised 65 patients with PTT less than 3 times the control value. Ischemic complications were analyzed on day 1 after PTCA and at hospital discharge. Bleeding complications and mortality were examined only at hospital discharge. There was a significant reduction in the incidence of abrupt coronary artery closure in group A on day 1 (1.5% vs 10.7%, p less than 0.001) and at hospital discharge (2.6% vs 10.7%, p less than 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency coronary artery bypass surgery following failed balloon angioplasty: role of the internal mammary artery graft

During a 4-year period (1986-1989), 3,502 patients had percutaneous transluminal coronary angioplasty (PTCA) in our institution. One hundred nineteen (3.4%) patients required emergency coronary artery bypass graft surgery (CABG) because of abrupt vessel closure following PTCA. Factors associated with vessel closure included lesion angulation greater than or equal to 90 degrees (p less than 0.007), the presence of thrombus (p less than 0.02), or a long (greater than or equal to 2 cm) lesion (p less than 0.03). Of these 119 emergency CABG patients, 108 (91%) arrived in the operating room in a stable condition (group I) and 11 (9%) were in cardiogenic shock (group II). Five (45%) of the group II patients were admitted to the hospital with an acute myocardial infarction and all 11 patients had a higher incidence of multivessel disease (p less than 0.05) and lower left ventricular ejection fraction (p less than 0.001) than group I patients. The overall surgical mortality was 10.1%; however, in group I the mortality was 5.6% and in group II it was 54.5% (p less than 0.001). The vessel that abruptly closed ("culprit vessel") was the left anterior descending (LAD) in 60%, the right coronary artery in 27%, and the left circumflex in 13%. The internal mammary artery was utilized to bypass the culprit artery in 51 (43%) patients, including 50% of the culprit LADs. With group I culprit LAD patients, when the left IMA was the bypass conduit, there were no hospital deaths nor strokes and there was a 6.3% incidence of perioperative infarction.

Usefulness of morphologic parameters in predicting the outcome of coronary excimer laser angioplasty

The treatment of complex coronary lesions with conventional balloon angioplasty is associated with a reduced success rate and an increased incidence of complications. To evaluate the influence of lesion morphology on the outcome of coronary excimer laser angioplasty, morphologic parameters of 148 target lesions in 147 consecutive patients were determined. Morphologic analysis included target vessel, involved vessel segment, vessel diameter, minimal lumen diameter, length of the lesion, single discrete (concentric/eccentric) or complex lesions (occlusions, bifurcational, tandem or long segmental lesions), American College of Cardiology/American Heart Association Task Force classification, lesion location in curved or straight vessel segments, prestenotic vessel tortuosity and the direction of the laser approach in curved vessels with eccentric lesions. Failure of laser angioplasty occurred in 17 patients because of failed guidewire placement (n = 8), catheter placement (n = 6), or inability to pass the lesion with the laser catheter (n = 3). Successful stand-alone laser angioplasty was achieved in 68 procedures. In 63 interventions additional balloon angioplasty was necessary (n = 60) or stand-alone laser angioplasty was not successful (n = 3). The frequency of complex lesions, particularly total occlusions (p less than 0.001) and prestenotic vessel tortuosity (p = 0.002) was significantly increased in the group with failed laser attempts. Statistical analysis of the morphologic parameters in successful stand-alone laser interventions compared with combined or unsuccessful interventions revealed no significant difference. These data suggest that failure of laser angioplasty occurs because of low catheter flexibility and the need for guidewire support in treating totally occluded vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty in ulcerative coronary artery disease: acute results and early follow-up

The safety and efficacy of percutaneous transluminal coronary angioplasty (PTCA) for stenoses involving ulcerative lesions were retrospectively studied. Seventy-seven patients (62 men and 15 women, mean age 62 +/- 10 years) representing 3.4% of 2,250 patients treated with PTCA during the period January 1, 1988 and June 30, 1990, had pre-PTCA stenoses defined as ulcerated. Twenty-eight (36%) of the stenoses were localized in the left anterior descending coronary artery, 9 (12%) in the left circumflex and 40 (52%) in the right coronary artery. During angioplasty, percent diameter stenosis was reduced from 73 +/- 14% to 22 +/- 13% and transstenotic gradient decreased from 48 +/- 18 to 12 +/- 6 mm Hg. Clinical success (freedom from angina at discharge without coronary bypass surgery, infarction or death) was achieved in 70 patients (90.9%). There were seven unsuccessful cases: three underwent elective coronary bypass surgery, one was managed medically, and three developed a major flow interrupting dissection during the procedure requiring emergency coronary bypass surgery. There were no deaths. At mean follow-up of 7.6 months, 45 of 61 patients (73.7%) remained asymptomatic. One patient needed an elective coronary bypass surgery and five patients had a successful repeat PTCA. In conclusion, PTCA for an ulcerated stenosis can be performed safely with a high primary success rate and a favorable early clinical course.

Percutaneous transluminal coronary angioplasty for unstable angina

Coronary angioplasty is an effective treatment for patients with angina at rest, either refractory or initially stabilized but returning despite pharmacologic treatment, and with early postinfarction angina. The procedure has a high initial success rate, but there is an increased risk of major complications resulting from a higher incidence of acute closure, which may be related to preexisting thrombus. Resolution of this problem may be achieved by the use of more potent antiplatelet treatment, pretreatment with thrombolytic agents, or treatment that can be applied locally (e.g., laser energy, atherectomy) at the site of the unstable plaque. Results in this study have been obtained from selected groups of patients: those with predominantly single-vessel disease and well-preserved left ventricular function. It remains to be determined whether the same benefits can be achieved in patients with multivessel disease or in those who have severely reduced left ventricular function.

Use of a morphologic classification to predict clinical outcome after dissection from coronary angioplasty

To determine if morphology of procedure-associated dissections could help predict clinical outcome, angiograms of 691 coronary artery dissections resulting from percutaneous transluminal coronary angioplasty were categorized according to the National Heart, Lung, and Blood Institute classification system. Classes of dissection were then correlated with clinical outcome: 543 patients with type B dissections had no increase in morbidity and mortality when compared with patients without dissection, with a similar success rate of 93.7%. Complications in this group were low and compared favorably with complication rates in procedures not associated with dissection. One hundred forty-eight procedures associated with dissections of types C to F had a significant increase in in-hospital complications, including acute closure (31%), need for emergency coronary bypass surgery (37%), myocardial infarction (13%) and repeat angioplasty (24%). The overall clinical success rate for those with types C to F dissection was 38%. The differences in clinical success and acute complications between type B and types C to F dissections were statistically significant at p less than 0.0005 for all variables studied. The angiographic morphology of a dissection during coronary angioplasty can predict clinical outcome, aiding in selection of effective therapy.

Influence of contrast media on thrombus formation during coronary angioplasty

The influence of contrast media on thrombus formation during percutaneous transluminal coronary angioplasty was assessed in 124 consecutive patients undergoing coronary angioplasty and receiving either ionic (n = 57) (Group I) or nonionic (n = 67) (Group II) contrast medium. The presence of thrombus was assessed by qualitative analysis of angiograms in identical pre- and postangioplasty projections by four observers who had no knowledge of other data. Quantitation of stenosis severity before and after angioplasty and qualitative analysis of lesion eccentricity and complexity and of the presence of dissection were also performed. Although the baseline clinical characteristics of the two groups (including presenting syndromes and procedural and angiographic variables) did not differ, more patients in Group II than Group I developed new thrombus during coronary angioplasty (18% vs. 4%, p less than 0.02). In particular, patients with a presenting syndrome of recent myocardial infarction or rest angina, or both, and patients with an eccentric coronary plaque were more likely to develop new thrombus if they received nonionic than if they received ionic contrast medium (p less than 0.05). Patients with new thrombus formation and patients with thrombus present both before and after angioplasty had a high incidence of acute procedural complications (36% and 23%, respectively). Patients in Groups I and II had a similar incidence of ischemic events during follow-up.

Same-day angioplasty and diagnostic catheterization: safe and effective but riskier in unstable angina

Percutaneous transluminal coronary angioplasty was performed at the time of the diagnostic catheterization in 188 patients (215 lesions) at a University Hospital in order to assess the efficacy of this approach and the potential role it should play in the evaluation and treatment of patients. Patients either presented for diagnostic catheterization for evaluation of stable coronary disease (79 patients) or for unstable or new onset anginal symptoms (109 patients). Lesions were graded as to whether they were simple or complex; and post angioplasty films were reviewed for success rate, and degree of revascularization. Patients who were referred for stable anginal symptoms had a slightly higher success rate (91%) compared to those who were referred for new onset or more unstable symptomatology (85%, p = ns). Additionally, lesions morphology was judged to be more complex in unstable patients, as 67% had complex lesions with the presence of thrombus or ulcerated plaque in 56% of these stenoses. Angioplasty success was high for simple lesions in all patients, but was most unfavorable for complex stenoses in patients who presented with unstable symptoms (81% success rate). In patients who presented with new onset or unstable symptoms multivessel disease was present in 69% and angioplasty was more often geared at dilating a culprit stenosis leaving only 49% of these patients with complete revascularization. On the other hand, in 76% of those patients who presented with stable angina complete revascularization was a common outcome. Length of hospital stay was considerably shorter at 2.9 +/- 0.8 days in those patients who presented with stable symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Twelve-lead electrocardiographic evaluation of ischemia during percutaneous transluminal coronary angioplasty and its correlation with acute reocclusion

The sensitivity of the surface 12-lead electrocardiogram and that of standard (limb-lead) monitoring for the detection of ischemia during percutaneous transluminal coronary angioplasty were compared in 115 patients. The purpose was to identify the electrocardiographic leads that provide the most sensitive indicators of coronary ischemia during percutaneous transaluminal coronary angioplasty and to evaluate the "ischemic fingerprint" that is obtained with 12-lead electrocardiogram during balloon inflation as a predictor of abrupt reocclusion after successful percutaneous transaluminal coronary angioplasty procedures. During balloon inflations of 30 seconds, ischemia was detected in 61 of 145 vessels (42%) by limb-lead monitoring alone versus 130 of 145 vessels (90%) by 12-lead electrocardiography (p less than or equal to 0.001). In the nine patients (7.8%) who experienced abrupt reocclusion within 24 hours, the electrocardiogram during chest pain after percutaneous transaluminal coronary angioplasty was identical to that obtained during percutaneous transaluminal coronary angioplasty ("ischemic fingerprint"). None of the six patients who had chest pain after percutaneous transaluminal coronary angioplasty without evidence of abrupt reocclusion reproduced their ischemic fingerprint. The suggested optimal leads for monitoring ischemia are as follows: left anterior descending coronary artery, V2, and V3; circumflex artery, V2, and V3; and right coronary artery, III and aVF.

Outcome after major dissection during coronary angioplasty using the perfusion balloon catheter

Coronary artery dissection is an infrequent but serious complication of coronary angioplasty that can lead to periprocedural vessel occlusion, emergency bypass surgery, myocardial infarction or death. Recently, a perfusion balloon catheter was developed that permits passive perfusion of blood through the central lumen of the catheter. It enables prolonged balloon inflations to be performed and has been used to provide distal blood flow after coronary occlusion. To evaluate the effectiveness of the perfusion balloon catheter in patients with major coronary dissections, 36 consecutive patients treated with the perfusion balloon catheter were compared with 46 consecutive patients treated before its availability. The 2 groups were similar in terms of clinical, angiographic and initial procedural characteristics. Use of the perfusion balloon catheter permitted a significantly longer inflation than standard balloon inflation (average 18 +/- 5 min). Angiographic success was significantly greater with the perfusion balloon catheter (84 vs 62% for conventional therapy), whereas complications were markedly reduced (48 vs 78%). With the perfusion balloon catheter there were fewer deaths (2 vs 6%), myocardial infarctions (14 vs 40%) and emergency bypass operations (11 vs 25%). The findings of this retrospective comparison demonstrate that the perfusion balloon catheter is effective for the management of major dissections after coronary angioplasty. The use of the perfusion balloon catheter should be considered when a major coronary dissection occurs and when emergency bypass surgery is contemplated.

Relation of stenosis resolution pressure to long-term clinical outcome after successful percutaneous transluminal coronary angioplasty

Variables associated with a poor long-term prognosis after successful percutaneous transluminal coronary angioplasty (PTCA) include a short duration of symptoms before PTCA, unstable angina and the presence of thrombus at the PTCA site. These imply a component of transient or dynamic obstruction as opposed to a pure fixed obstruction. It is postulated that resolution pressure (i.e., the pressure at which complete balloon inflation occurs) may also correlate with prognosis after successful PTCA. In 173 consecutive patients undergoing successful, elective, single-lesion PTCA, 48 (28%) were found to have narrowings that resolved at less than or equal to 2 atm (group 1) and 125 (72%) were found to have narrowings resolved at greater than 2 atm (group 2). There were no significant differences in baseline, anatomic or procedural variables between the 2 groups, except that angiographic coronary dissection occurred in 17% of group 1 patients versus 40% of group 2 patients (p less than 0.007). During a mean follow-up of 12.0 +/- 6.1 months, the incidence of cardiac events (repeat PTCA, coronary artery bypass grafting or myocardial infarction) was 29% in group 1 versus 15% in group 2 (p less than 0.05). The overall incidence of angina was similar between the groups (25 vs 28%), but Canadian Cardiovascular Association class 4 angina occurred significantly more frequently in group 1 than group 2 (21 vs 8%) (p less than 0.04). These data suggest that a low resolution pressure is associated with a higher incidence of unstable angina and recurrent cardiac events during follow-up than higher resolution pressures.