Accuracy and interobserver variability of coronary cineangiography: a comparison with postmortem evaluation

Comparison of Invasive Coronary Angiography Versus Computed Tomography Angiography to Assess Mehran Classification of In-Stent Restenosis in Bifurcation Percutaneous Coronary Intervention

The Mehran classification is used to determine the presence of in-stent restenosis (ISR) and characterization of its subtypes in invasive coronary angiography (ICA). The utility of computed tomography angiography (CTA) for the assessment of Mehran classification is unknown. We aimed to compare the agreement and reproducibility of Mehran classification between ICA and CTA and evaluate the sensitivity and specificity of both imaging methods. Consecutive patients who had ISR on ICA preceded with CTA before intervention were enrolled in our study. Modified Mehran's classification was employed by CTA and ICA to classify ISR into 4 subtypes: focal (type I [A, B, C]), intra-stent (type II [A, B, C]), proliferative (type III [A, B, C]), and total occlusion (type IV). Agreement between ISR classification and main vessel lesion length, reference vessel diameter, and bifurcation angles were compared. A total of 405 patients with 431 bifurcation percutaneous coronary interventions with ISR were included in this investigation. The total agreement between CTA and ICA for assessment of Mehran class was poor (kappa = 0.168). Proliferative ISR (25% vs 10%, p = 0.012) and total occlusions (24% vs 5%, p <0.001) were reclassified more often between ICA and CTA, respectively. CTA assessment of lesion length was significantly longer than that of ICA measurements in all subtypes of ISR (32.15 ± 5.23 vs 27.41 ± 3.63, p = 0.004). Receiver operating characteristic curve expressed CTA to be more sensitive and specific than ICA in diagnosing ISR. In conclusion, Mehran classification was significantly affected by imaging modality, and CTA results were more reproducible than ICA. Therefore, CTA evaluation of ISR may facilitate treatment options and generate a sound plan before the procedure.

Mind the gap: Knowledge deficits in evaluating young sudden cardiac death

Sudden cardiac arrest affects around half a million people aged under 50 years old annually, with a 90% mortality rate. Despite high patient numbers and clear clinical need to improve outcomes, many gaps exist in the evidence underpinning patients' management. Domains identifying the greatest barriers to conducting trials are the prehospital and forensic settings, which also provide care to the majority of patients. Addressing gaps in evidence along each point of the cardiac arrest trajectory is a key clinical priority.

Coronary artery fixation at iso-arterial pressure: impacts on histologic evaluation and clinical management

Coronary angiography is the standard imaging method for determining the site, extent, and severity of coronary artery disease. Several publications have reported discordance between the degree of coronary artery stenosis determined from post-mortem histologic evaluation and coronary angiography. While the 2-dimensional limitations of coronary angiography are well established, the determination of coronary stenosis based on histologic evaluation of passively fixed samples is also associated with significant biases. In this study, we used patients with chronic coronary artery disease to compare the stenosis severity estimates that were determined using the passive fixation method with those determined using the active fixation method. Our results showed a significant discrepancy between the stenosis in passively fixed coronary arteries when compared with coronary angiography in all major coronary vessels combined (P=.002), and in Cx (P=.045) and CD (P=.026). However, there was no mean difference when compared with perfused (actively fixed) samples when all vessels were combined or examined individually. Iso-physiologic mechanical perfusion (active) fixation yielded significantly reduced coronary artery stenosis means when compared to the passive fixation method in post-mortem evaluations during autopsies. This was evident when all vessels were combined (P=.0001) and assessed individually (Cx (P=.003), LAD (P=.025), LM (P=.056) and RC (P=.007)). Autopsies including cardiac explant patients also showed differences in estimates for all vessels combined (P=.0001) and in Cx (P=.016) and RC (P=.006). In summary, our quantitative histopathology analyses using perfused coronary artery stenosis at physiologic pressure showed significant discrepancies when compared with passive histopathology.

Reaffirming the Value of the Autopsy

OBJECTIVES

To determine characteristic features of myocardial infarction (MI) diagnosed at autopsy and establish the incidence of discrepancy.

METHODS

Autopsy cases at a tertiary hospital with a pathologic diagnosis of acute MI were evaluated for clinicopathologic features. Modified Goldman's classification was used to classify discrepant cases.

RESULTS

Of 529 autopsy cases, 19 (3.6%) demonstrated acute/subacute MI as a pathologic diagnosis. Thrombosis was identified in a minority of cases (3/19, 15.8%). Major clinicopathologic discrepancies were identified in four (21.1%) cases.

CONCLUSIONS

Although acute MI is an uncommon diagnosis rendered at hospital autopsy, a notable subset of cases demonstrates diagnostic discrepancy between the clinical impression and ultimate pathologic diagnosis. Interestingly, most MI cases in this series are not related to plaque disruption and thus best classified as a type 2 MI, which is associated with imbalance between oxygen demand and supply.

The Current Status of Intervention for Intermediate Coronary Stenosis in the Korean Percutaneous Coronary Intervention (K-PCI) Registry

BACKGROUND AND OBJECTIVES

Intermediate coronary lesion that can be under- or over-estimated by visual estimation frequently results in stenting of functionally nonsignificant lesions or deferral of percutaneous coronary intervention (PCI) of significant lesions inappropriately. We evaluated current status of PCI for intermediate lesions from a standardized database in Korea.

METHODS

We analyzed the Korean percutaneous coronary intervention (K-PCI) registry data which collected a standardized PCI database of the participating hospitals throughout the country from January 1, 2014, through December 31, 2014. Intermediate lesion was defined as a luminal narrowing between 50% and 70% by visual estimation and then compared whether the invasive physiologic or imaging study was performed or not.

RESULTS

Physiology-guided PCI for intermediate lesions was performed in 16.8% for left anterior descending artery (LAD), 9.8% for left circumflex artery (LCX), 13.2% for right coronary artery (RCA). PCI was more frequently performed using intravascular ultrasound (IVUS) than using fractional flow reserve (FFR) for coronary artery segments (27.7% vs. 13.9% for LAD, 32.9% vs. 8.1% for LCX, and 33.8% vs. 10.8% for RCA). In accordance with or without FFR, PCI for intermediate lesions was more frequently performed in the hospitals with available FFR device than without FFR, especially in left main artery (LM), proximal LAD lesion (40.9% vs. 5.9% for LM, 24.6% vs 7.6% for proximal LAD).

CONCLUSIONS

These data provide the current PCI practice pattern with the use of FFR and IVUS in intermediate lesion. More common use of FFR for intermediate lesion should be encouraged.

Comparison of Fractional FLow Reserve And Intravascular ultrasound-guided Intervention Strategy for Clinical OUtcomes in Patients with InteRmediate Stenosis (FLAVOUR): Rationale and design of a randomized clinical trial

BACKGROUND

Coronary angiography has limitations in defining the ischemia-causing stenotic lesion, especially in cases with intermediate coronary stenosis. Fractional flow reserve (FFR) is a current standard method to define the presence of ischemia, and intravascular ultrasound (IVUS) is the most commonly used invasive imaging tool that can provide the lesion geometry and can provide the information on plaque vulnerability. The primary aim of this study is to compare the safety and efficacy of FFR-guided and IVUS-guided percutaneous coronary intervention (PCI) strategies in patients with intermediate coronary stenosis.

TRIAL DESIGN

Comparison of Fractional FLow Reserve And Intravascular ultrasound-guided Intervention Strategy for Clinical OUtcomes in Patients with InteRmediate Stenosis (FLAVOUR) trial is an international, multicenter, prospective, randomized clinical trial. A total of 1,700 consecutive patients with intermediate stenosis (40%-70% by visual estimation) in a major epicardial coronary artery will be randomized 1:1 to receive either FFR-guided or IVUS-guided PCI strategy. Patients will be treated with PCI according to the predefined criteria for revascularization; FFR ≤ 0.80 in the FFR-guided group and Minimal Lumen Area (MLA) ≤3 mm² (or 3 mm²<MLA ≤4 mm² and plaque burden >70%) in the IVUS-guided group. The primary end point is the patient-oriented composite outcome, which is a composite of all-cause death, myocardial infarction, and any repeat revascularization at 24months after randomization. We will test noninferiority of current standard FFR-guided PCI strategy compared with IVUS-guided decision for PCI and stent optimization strategy.

CONCLUSION

The FLAVOUR trial will compare the safety and efficacy of FFR- and IVUS-guided PCI strategies in patients with intermediate coronary stenosis. This study will provide an insight on optimal evaluation and treatment strategy for patients with intermediate coronary stenosis.

Meta-analysis of the effects of lifestyle modifications on coronary and carotid atherosclerotic burden

Lifestyle modifications are the crux of atherosclerotic disease management. The goal of this study was to determine the effectiveness of diet and exercise in decreasing coronary and carotid atherosclerotic burden. Randomized controlled trials examining the effects of intensive lifestyle measures on atherosclerotic progression in coronary and carotid arteries as measured by baseline and follow-up quantitative coronary angiogram and ultrasonographic carotid intimal-medial thickness (CIMT), respectively, were included. Studies were excluded if the intervention additionally included a medication. MEDLINE, EMBASE, CINAHL, Cochrane Controlled Trials Registers, reports, and abstracts from major cardiology meetings were searched by 2 researchers independently and verified by the primary investigator. Standardized mean difference (SMD) with 95% confidence intervals (CIs) was calculated using random-effects model. Publication bias and heterogeneity were assessed. Fourteen trials were included. Seven used quantitative coronary angiogram, and 7 used CIMT; 1,343 lesions in 340 patients in the coronary group and 919 patients in the carotid group were analyzed. Overall, lifestyle modifications were associated with a decrease in coronary atherosclerotic burden in percent stenosis by -0.34 (95% CI -0.48 to -0.21) SMD, with no significant publication bias and heterogeneity (p = 0.21, I(2) = 28.25). Similarly, in the carotids, there was a decrease in the CIMT, in millimeter, by -0.21 (95% CI -0.36 to -0.05) SMD and by -0.13 (95% CI -0.25 to -0.02) SMD, before and after accounting for publication bias and heterogeneity (p = 0.13, I(2) = 39.91; p = 0.54, I(2) = 0), respectively. In conclusion, these results suggest that intensive lifestyle modifications are associated with a decrease in coronary and carotid atherosclerotic burden.

Coronary atherosclerotic lesions in patients with a ruptured abdominal aortic aneurysm

In this study, the coronary findings in 185 autopsy cases with a ruptured abdominal aortic aneurysm (AAA) from the Tokyo Medical Examiner's Office were examined and compared with those in 1,056 patients undergoing AAA repair at the University of Tokyo Hospital or Sakakibara Heart Institute (Tokyo, Japan). The number of cases with any significant coronary stenosis was significantly greater in the autopsy cases with a ruptured AAA than in the patients undergoing emergency repair of a ruptured AAA, suggesting that the low prevalence of CAD observed in patients undergoing emergency repair of a ruptured AAA was due to the survival bias before reaching hospital. In addition, we also found that significant coronary left main trunk stenosis was more frequent in CAD cases with a ruptured AAA than in those with an unruptured AAA, findings that suggest novel clinical implications. Large-scale prospective studies are warranted to confirm our findings and to clarify the pathophysiological relationship between coronary atherosclerosis and AAA status.

Angiographic validation of the American College of Cardiology Foundation-the Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies study

BACKGROUND

The goal of this study was to compare angiographic interpretation of coronary arteriograms by sites in community practice versus those made by a centralized angiographic core laboratory.

METHODS AND RESULTS

The study population consisted of 2013 American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) records with 2- and 3- vessel coronary disease from 54 sites in 2004 to 2007. The primary analysis compared Registry (NCDR)-defined 2- and 3-vessel disease versus those from an angiographic core laboratory analysis. Vessel-level kappa coefficients suggested moderate agreement between NCDR and core laboratory analysis, ranging from kappa=0.39 (95% confidence intervals, 0.32-0.45) for the left anterior descending artery to kappa=0.59 (95% confidence intervals, 0.55-0.64) for the right coronary artery. Overall, 6.3% (n=127 out of 2013) of those patients identified with multivessel disease at NCDR sites had had 0- or 1-vessel disease by core laboratory reading. There was no directional bias with regard to overcall, that is, 12.3% of cases read as 3-vessel disease by the sites were read as <3-vessel disease by the core laboratory, and 13.9% of core laboratory 3-vessel cases were read as <3-vessel by the sites. For a subset of patients with left main coronary disease, registry overcall was not linked to increased rates of mortality or myocardial infarction.

CONCLUSIONS

There was only modest agreement between angiographic readings in clinical practice and those from an independent core laboratory. Further study will be needed because the implications for patient management are uncertain.

Assessment of coronary artery stenosis by coronary angiography: a head-to-head comparison with pathological coronary artery anatomy

BACKGROUND

Conventional coronary angiography (CCA) has been considered as a gold standard for the diagnosis of coronary artery diseases; however, its diagnostic accuracy is still unknown.

METHODS AND RESULTS

Between July 2004 and December 2011, 97 patients underwent CCA within 15 days before heart transplantation in Fuwai hospital. A head-to-head comparison study was performed to examine the diagnostic accuracy of CCA as compared with that of pathological coronary artery anatomy. As confirmed by pathological coronary artery anatomy, 44 (45.4%) patients had coronary artery diseases. The patient-based diagnostic accuracy evaluation showed that the area under the receiver-operating characteristic curve of CCA for detecting ≥50% stenosis was 0.91, with a sensitivity of 91%, a specificity of 93%, and high concordance (κ=0.83). A per-vessel analysis of 291 vessels yielded an AUC of 0.79, the agreement of 3 vessels >0.6 (κ statistic). The area under the receiver-operating characteristic curve was 0.88 for proximal and middle segments, and was 0.62 for distal segments, κ was calculated to detect the distal segments with lower concordance than proximal and middle segments. The patient- and vessel-based evaluations showed similar diagnostic accuracy of CCA in detecting ≥75% stenosis. Per-segment evaluation found CCA was more accurate for detecting ≥50% and ≥75% stenosis in proximal and middle segments than in distal segments, and the diagnosis ability decreased in more severe stenosis segments and more complex lesions.

CONCLUSIONS

The accuracy of CCA is quite high in detecting coronary artery stenosis in patients- and vessels-based levels. However, the diagnosis ability decreased in more severe and complex lesions, especially for distal segments.

Postmortem angiography: review of former and current methods

OBJECTIVE

Postmortem investigations are becoming more and more sophisticated. CT and MRI are already being used in pathology and forensic medicine. In this context, the impact of postmortem angiography increases because of the rapid evaluation of organ-specific vascular patterns, vascular alteration under pathologic and physiologic conditions, and tissue changes induced by artificial and unnatural causes.

CONCLUSION

In this article, the advantages and disadvantages of former and current techniques and contrast agents are reviewed.

Toll-like receptor 4 polymorphism is associated with coronary stenosis but not with the occurrence of acute or old myocardial infarctions

OBJECTIVE

Atherosclerosis is considered to be a chronic inflammatory disease. Toll-like receptor 4 (TLR-4), a key mediator in activating inflammatory cascade, has an A-to-G functional polymorphism that changes aspartic acid to glycine at position 299. TLR-4 is activated by, for example, lipopolysaccharides. The purpose of this study was to investigate the role of a common Asp299Gly polymorphism of the TLR-4 gene in atherosclerosis.

MATERIAL AND METHODS

The study comprised autopsy material from 657 men (the Helsinki Sudden Death Study; mean age 53, range 33-70 years).

RESULTS

Fewer G-allele carriers had 3-vessel coronary artery disease compared with AA homozygotes (OR 0.32; 95 % CI, 0.12-0.88, p = 0.027), and they also had a lower mean value for maximal coronary stenosis (p = 0.019). TLR-4 polymorphism was not significantly associated with the occurrence of acute or old myocardial infarction (MI).

CONCLUSIONS

The G allele of the TLR-4 gene, which is associated with a lower inflammation response, was associated with a lower risk of coronary stenosis but not with the occurrence of MI and hence is not a major factor in the development of coronary atherosclerosis.

Second reading of coronary angiograms by radiologists

BACKGROUND

In many hospitals in the provinces of Quebec and Nova Scotia, as well as in some hospitals in the rest of Canada, coronary angiograms are performed and interpreted by invasive cardiologists, and are later reinterpreted and reported by radiologists.

OBJECTIVE

To evaluate the value of second readings of coronary angiograms by radiologists.

METHODS

Cardiology and radiology reports of a total of 160 consecutive coronary angiograms were compared from patients at three hospitals. Ten segments of the coronary tree were considered and 1582 segments were included. Agreement between cardiology and radiology interpretations was evaluated using per cent agreement, Pearson correlation and Bland-Altman limits of agreement. Agreement was calculated for each arterial segment and for each hospital.

RESULTS

Excellent agreement was found between cardiology and radiology interpretations of coronary angiograms. Per cent agreement ranged from 94.9% to 100%, Pearson correlation ranged from 0.83 to 0.97 and Bland-Altman limits of agreement ranged from -18.1 to 19.4. Agreement was similar for each segment and for each hospital. Agreement remained excellent after exclusion of normal angiograms (n=348 segments), with a per cent agreement of 96.3%. Secondary analyses demonstrated a mean time delay of 13 days between angiograms and the subsequent radiology reports.

CONCLUSIONS

There are minimal differences between the cardiology and radiology interpretations of coronary angiograms. Routine second reading by a radiologist may be redundant.

MR aortography and serum cholesterol levels in patients with long-term nonspecific lower back pain

STUDY DESIGN

A cross-sectional analysis of the feeding arteries of the lumbar spine and cholesterol levels on patients with long-term nonspecific lower back pain.

OBJECTIVES

To evaluate whether occlusion of lumbar and middle sacral arteries or serum cholesterol levels are associated with lower back pain and/or with disc degeneration.

SUMMARY OF BACKGROUND DATA

Atherosclerosis in the wall of the abdominal aorta usually develops at the ostia of branching arteries and the bifurcation, and may obliterate orifices of lumbar and middle sacral arteries. Obstruction of these arteries causes ischemia in the lumbar spine and may result in back symptoms and disc degeneration.

METHODS

MR aortography and cholesterol blood tests were performed on 51 patients with long-term lower back pain without specific findings (i.e., spinal or nerve root compression) in regular lumbar MR images. The patients ranged from 35 to 70 years of age (mean age, 56 years). Serum cholesterol and low-density lipoprotein (LDL) cholesterol levels were measured. To assess symptoms and disability NASS low back Outcome Instrument was used.

RESULTS

Twenty-nine (78%) of 37 men and 11 (77%) of 14 women showed occluded lumbar and/or middle sacral arteries. The prevalence of occluded arteries was 2.5 times more than in subjects of corresponding age group in a Finnish necropsy material. Twenty-three (62%) men and seven (50%) women had significant disc degeneration. Disc degeneration was associated with occluded lumbar/middle sacral arteries (P = 0.035). Patients with occluded arteries or significant disc degeneration did not complain more severe symptoms than those without, whereas patients with above normal serum LDL cholesterol scored higher in neurogenic symptoms (P = 0.031) and complained more often severe pain (P = 0.049) than those with normal LDL cholesterol.

CONCLUSIONS

The study indicates that lumbar and middle sacral arteries are often occluded in patients with nonspecific long-term lower back pain. Occlusion of these arteries may also be associated with disc degeneration.

The time has come to reexamine the gold standard when evaluating noninvasive testing

Angiographically identified 50% cross-sectional narrowing of a coronary artery fails to accurately identify compromised myocardial perfusion. Noninvasive tests should be correlated with intravascular ultrasound or coronary flow reserve to determine their clinical utility.

Evaluation of the role of abciximab (Reopro) as a rescue agent during percutaneous coronary interventions: in-hospital and six-month outcomes

Abciximab is effective for the prevention of complications when administered prior to percutaneous coronary intervention (PCI). The efficacy and safety of abciximab as an unplanned or rescue agent for complications of PCI is unknown. Rescue versus planned use was compared in 186 consecutive patients. Primary or rescue PCI for acute myocardial infarction (MI) and shock were excluded. Rescue abciximab use was undertaken in 101 patients (54.3%) and planned abciximab was used in 85 (45.7%). The rescue abciximab patients had a lower incidence of previous MI, preprocedural thrombus, multivessel, and vein graft intervention. In-hospital endpoints in the rescue versus planned abciximab patients were death (1.0% vs. 1. 2%, P = 1.0), Q-wave MI (2.0% vs. 2.4%, P = 1.0), any MI (14.9% vs. 9.4%, P = 0.3), target vessel revascularization (TVR; 0% vs. 1.2%, P = 1.0), and composite (15.8% vs. 10.6%, P = 0.3). At 6 months, events were death (4.0% vs. 2.3%, P = 0.69), MI (14.9% vs. 9.4%, P = 0.26), TVR (20.8% vs. 4.7%, P = 0.001), and composite (30.7% vs. 15. 3%, P = 0.01). In-hospital complications between the rescue and planned abciximab patients of major bleed (1.0% vs. 1.8%, P = NS), stroke (0% vs. 1.8%, P = NS), and thrombocytopenia (3.0% vs. 1.8%, P = NS) were similar. There was a significantly higher procedural time (99.6 min vs. 86.1 min, P = 0.02), contrast volume (278.8 ml vs. 223. 5 ml, P = 0.04), and heparin use (8984 u vs. 6003 u, P = 0.0006) in the rescue group. In this nonrandomized comparison, rescue abciximab allowed for the safe discharge from hospital in the majority of patients. However, during a 6-month follow-up, more patients treated with rescue abciximab required TVR with either repeat PCI or CABG. Further studies are warranted to evaluate the overall strategy of rescue abciximab use in PCI.

Internal mammary artery graft angioplasty: acute and long-term outcome

Secondary to the low attrition rate of internal mammary artery grafts, limited data are available on the clinical and angiographic outcome of patients who have undergone balloon angioplasty of an internal mammary artery stenosis. This study examined a consecutive series of 68 patients who underwent balloon angioplasty of an internal mammary artery graft over a 9-year period. Procedural success was achieved in 60 of 68 (88%) patients. The primary reason for procedural failure was extreme vessel tortuosity. There were no major in-hospital complications. Angiographic follow-up was obtained in 78% of the patients with an angiographic restenosis rate of 19%. The overall event-free survival in patients with an initially successful procedure was 92%. In conclusion, internal mammary artery balloon angioplasty has both an excellent initial success rate as well as a low incidence of restenosis and repeat target lesion revascularization.

"Rescue" utilization of abciximab for the dissolution of coronary thrombus developing as a complication of coronary angioplasty

OBJECTIVES

This study sought to test the effect on thrombus score of the "rescue" utilization of the glycoprotein IIb/IIIa antagonist abciximab given to patients in whom intracoronary thrombus has developed as a complication after percutaneous transluminal coronary angioplasty (PTCA) and to determine its clinical utility.

BACKGROUND

Abciximab is effective in the prevention of acute ischemic complications when given prophylactically to patients during high risk PTCA. However, its ability to therapeutically dissolve newly formed intracoronary thrombus occurring as a complication after PTCA is not known.

METHODS

We performed an observational study in 29 consecutive patients who received abciximab (0.25 mg/kg body weight intravenous bolus, followed by a 12-h infusion at 10 microg/min) after attempted PTCA caused either the new development or further progression of thrombus. Angiograms were analyzed to determine thrombus score and Thrombolysis in Myocardial Infarction (TIMI) flow grade before and after abciximab. Procedural and clinical success and long-term outcome were also determined.

RESULTS

Thrombus score decreased from 3.0 +/- 0.9 (mean +/- SD) to 0.86 +/- 0.92 (p < 0.001), and TIMI flow grade increased from 2.5 +/- 0.7 to 2.9 +/- 0.3 (p = 0.008). No instances of distal embolization or no-reflow were noted. The procedural success (< or = 50% residual stenosis) rate was 97%. The clinical success (procedural success with no in-hospital myocardial infarction, bypass surgery or death) rate was 93%.

CONCLUSIONS

Dissolution of thrombus and restoration of TIMI grade 3 flow were readily achieved after administration of abciximab when delivered in a "rescue" manner after the development of thrombosis after PTCA. This novel use of abciximab will need to be validated in randomized trials.

Prevalence of stenotic changes in arteries supplying the lumbar spine. A postmortem angiographic study on 140 subjects

OBJECTIVES

To study the prevalence of arterial diseases in the arteries supplying the lumbar spine and their relation to other vascular diseases, as well as to chronic low back pain.

METHODS

Five pairs of the lumbar arteries and the middle sacral artery were evaluated from 140 postmortem aortograms, performed in connection with routine medicolegal necropsies on subjects ranging from 16 to 89 years of age. For information about low back pain history, a close relative of each of the deceased was interviewed two to four weeks after the necropsy.

RESULTS

Twenty one (22%) men and nine (20%) women had occluded arteries, and an additional 33 (35%) men and 17 (38%) women had narrowed arteries. The mean age for men with occluded or narrowed arteries, or both, was 50 years and for women 59 years. Most of the stenotic changes were seen at the orifices or in the first part of the arteries. The middle sacral artery was most often affected, followed by the fourth lumbar arteries. The number of collateral arteries increased with occluded (p < 0.001) and narrowed arteries (p = 0.001). Stenotic lumbar/ middle sacral arteries were found, on average, five years earlier than atherosclerosis of the coronary arteries. Subjects with one or more occluded/narrowed arteries were 8.5 times more likely to have suffered from chronic (that is, three months or longer) low back pain at some time during their life than were those without such findings (odds ratio adjusted for age and sex 8.5; 95% confidence intervals 2.9, 24; p < 0.001).

CONCLUSIONS

The study shows that the lumbar and middle sacral arteries frequently become obliterated by atheromatous lesions during adult life, and that obliteration of these arteries is more common in subjects with a history of chronic back pain than in those without.

Racial variation in the use of coronary-revascularization procedures. Are the differences real? Do they matter?

BACKGROUND

Studies have reported that blacks undergo fewer coronary-revascularization procedures than whites, but it is not clear whether the clinical characteristics of the patients account for these differences or whether they indicate underuse of the procedures in blacks or overuse in whites.

METHODS

In a study at Duke University of 12,402 patients (10.3 percent of whom were black) with coronary disease, we calculated unadjusted and adjusted rates of angioplasty and bypass surgery in blacks and whites after cardiac catheterization. We also examined patterns of treatment after stratifying the patients according to the severity of disease, angina status, and estimated survival benefit due to revascularization. Finally, we compared five-year survival rates in blacks and whites.

RESULTS

After adjustment for the severity of disease and other characteristics, blacks were 13 percent less likely than whites to undergo angioplasty and 32 percent less likely to undergo bypass surgery. The adjusted black:white odds ratios for receiving these procedures were 0.87 (95 percent confidence interval, 0.73 to 1.03) and 0.68 (95 percent confidence interval, 0.56 to 0.82), respectively. The racial differences in rates of bypass surgery persisted among those with severe anginal symptoms (31 percent of blacks underwent surgery, vs. 45 percent of whites, P<0.001) and among those predicted to have the greatest survival benefit from revascularization (42 percent vs. 61 percent, P<0.001). Finally, unadjusted and adjusted rates of survival for five years were significantly lower in blacks than in whites.

CONCLUSIONS

Blacks with coronary disease were significantly less likely than whites to undergo coronary revascularization, particularly bypass surgery - a difference that could not be explained by the clinical features of their disease. The differences in treatment were most pronounced among those predicted to benefit the most from revascularization. Since these differences also correlated with a lower survival rate in blacks, we conclude that coronary revascularization appears to be underused in blacks.

Lesion-directed administration of alteplase with intracoronary heparin in patients with unstable angina and coronary thrombus undergoing angioplasty

Percutaneous coronary revascularization in patients with unstable angina and coronary thrombus carries a high complication rate. A new strategy to reduce thrombus burden before revascularization was tested in a multicenter prospective trial. Patients with unstable angina and coronary thrombus (n = 45) received alteplase through an infusion catheter at the proximal aspect of the target lesion and concomitant intracoronary heparin via a standard guiding catheter. Angiography was performed before and alter lesion-directed therapy and post-intervention. Systemic fibrinogen depletion and thrombin activation were not observed, while fibrinolysis was evident for > or = 4 hr after treatment. Target lesion stenosis did not change significantly after lesion-directed therapy, but thrombus score was reduced, particularly among patients who had large thrombi (mean 2.2 vs. 1.6, P = 0.02). Revascularization was successful in 89% of patients. Median final stenosis was 30% and mean final thrombus score was 0.4. Complications included recurrent ischemia (11%), MI (7%), abrupt closure (7%), severe bleeding (4%), and repeat emergency angioplasty (2%). Patients with overt thrombus appeared to derive the most angiographic benefit from lesion-directed alteplase plus intracoronary heparin. Later revascularization was highly successful. This strategy may be a useful adjunct to percutaneous revascularization for patients with unstable angina and frank intracoronary thrombus.

Analysis and comparison of operator-specific outcomes in interventional cardiology. From a multicenter database of 4860 quality-controlled procedures

BACKGROUND

Medical consumers are increasingly requesting methods to discriminate among the results of different providers. Standards for appropriate modeling, risk adjustment, and evaluation ("scorecarding") in this setting are not well developed, although such evaluation is being performed by the medical insurance industry and by several states in the United States. Our objectives were to develop and examine clinically meaningful methodology for assessing the operator-specific results for percutaneous coronary revascularization.

METHODS AND RESULTS

From a multicenter database of patients treated since January 1, 1990, we used training and validation samples (n = 4860) to develop several models for risk adjustment and applied them to 38 providers performing 25 to 523 procedures in the database. Models were developed using multivariable logistic regression techniques for combinations of the end points of death, myocardial infarction, bypass surgery, and procedural success. Models were evaluated for predictive accuracy by using receiver operating characteristic (ROC) analysis, for the capacity to discriminate between superior and inferior provider outcomes, and for subjectivity and concordance. Major complications occurred in 3.6% of patients. The area under the ROC curve (with perfect discriminatory accuracy, area = 1.0; with no apparent accuracy, area = 0.5) in the validation sample, and frequency of identification of operators with outcomes outside the 95% CI for the outcome in question for the models were for death, 0.85 and 7.9%; for death, Q-wave infarction, and bypass surgery, 0.77 and 13.2%; for death, all infarction, and bypass surgery, 0.66 and 10.5%; and for procedural success, 0.76 and 23.7%. For the models as a group, identification of outliers was inversely related to provider volume (P = .05). Models evaluating non-Q-wave infarction or requiring measurement of percent diameter stenosis were identified as being most susceptible to provider manipulation.

CONCLUSIONS

For percutaneous coronary revascularization, modeling to discriminate between provider outcomes is limited by the low incidence of major adverse events, subjectivity or susceptibility to manipulation of more frequently occurring adverse events, the generally modest predictive capacity of the models, and the low volume of individual provider treatments. Modeling will be most useful in the identification of providers with extremely poor outcomes and for discrimination between providers with very large procedural volume. Until improved understanding of the biological and mechanical correlates of major complications allows the development of more predictive models, interpretation of the results of scorecarding, particularly for low-volume providers, should be made with caution.

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.

Use of aortic counterpulsation to improve sustained coronary artery patency during acute myocardial infarction. Results of a randomized trial. The Randomized IABP Study Group

BACKGROUND

Aortic counterpulsation has been observed to reduce the rate of reocclusion of the infarct-related artery after patency has been restored during acute myocardial infarction in observational studies. To evaluate the benefit-to-risk ratio of aortic counterpulsation during the early phase of myocardial infarction, a multicenter randomized clinical trial was performed.

METHODS AND RESULTS

Patients who had patency restored during acute cardiac catheterization within the first 24 hours of onset of myocardial infarction were randomly assigned to aortic counterpulsation for 48 hours versus standard care. Intravenous heparin was used similarly in both groups and was continued for a median (25th, 75th percentile) of 5 (2,7) days. A total of 182 patients were enrolled; 96 were assigned to aortic counterpulsation and 86 to standard care. Repeat cardiac catheterization was performed at a median of 5 (4,6) days after randomization in 89% of patients assigned to aortic counterpulsation and in 90% of control patients. Patients randomized to aortic counterpulsation had similar rates of severe bleeding complications (2% versus 1%), number of units of blood transfused (mean, 1.3 +/- 2.6 versus 0.9 +/- 1.8 units), and vascular repair or thrombectomy (5% versus 2%) compared with patients treated in a conventional manner. Patients randomized to aortic counterpulsation had significantly less reocclusion of the infarct-related artery during follow-up compared with control patients (8% versus 21%, P < .03). In addition, there was a significantly lower event rate in patients assigned to aortic counterpulsation in terms of a composite clinical end point (death, stroke, reinfarction, need for emergency revascularization with angioplasty or bypass surgery, or recurrent ischemia): 13% versus 24%, P < .04.

CONCLUSIONS

This randomized trial showed that careful use of prophylactic aortic counterpulsation can prevent reocclusion of the infarct-related artery and improve overall clinical outcome in patients undergoing acute cardiac catheterization during myocardial infarction.

A randomized comparison of the effects of gradual prolonged versus standard primary balloon inflation on early and late outcome. Results of a multicenter clinical trial. Perfusion Balloon Catheter Study Group

BACKGROUND

Observational studies have suggested that prolonged balloon inflation during coronary angioplasty is associated with a high clinical success rate. This randomized clinical trial sought to evaluate the impact of primary gradual and prolonged inflations versus standard short dilatations in patients undergoing elective angioplasty.

METHODS AND RESULTS

In phase 1 of the study, patients were randomized to receive two to four standard (1 minute) dilatations or one or two prolonged (15 minutes) dilatations after a perfusion balloon had been placed across a single target lesion. Patients with unsuccessful angiographic appearance after phase 1 dilatations had further dilatations in phase 2. Patients were followed for 6 to 12 months after the procedure. Of 478 patients, 242 received a median of one prolonged dilatation of 15 minutes' duration, and 236 received three dilatations for a median of 1 minute. Patients assigned to prolonged dilatations had a higher success rate (< or = 50% residual visual stenosis) (95% versus 89%; P = .016), less severe residual stenosis by quantitative angiography (median [25th and 75th percentiles], 35% [26%, 42%] versus 38% [30%, 46%]; P = .001), and a lower rate of major dissections (3% versus 9%; P = .003) at the end of phase 1. A total of 114 patients had further dilatations in phase 2-43 in the prolonged arm and 71 in the standard arm. The final procedural success rate was 98% with both primary dilatation strategies, which included additional maneuvers such as prolonged dilatations in the patients randomized to the primary standard dilatation. Overall, 320 of 416 patients (77%) who were discharged after a successful procedure without any in-hospital event (death, myocardial infarction, coronary artery bypass graft surgery, abrupt closure, or repeat angioplasty in target vessel) returned for follow-up angiography. The restenosis rate (> 50% residual visual stenosis) was 44% (95% confidence interval, 37% to 52%) in the prolonged dilatation group and 44% (36% to 52%) in the standard dilatation group. The primary angiographic end point of failure at the end of phase 1, abrupt closure, or restenosis throughout the study period was similar in both groups (prolonged, 51%; standard, 49%; P = .62). The secondary end point of absence of clinical events (death, nonfatal myocardial infarction, coronary artery bypass graft surgery, or repeat angioplasty in target vessel) also was similar (prolonged, 66%; standard, 74%; P = .15).

CONCLUSIONS

Primary gradual and prolonged dilatations caused less arterial trauma with a modestly larger arterial lumen compared with standard dilatations. This initial improvement in angiographic appearance did not lead to a significant reduction in restenosis or clinical adverse events during follow-up.

Stenting of a renal artery stenosis achieves better relief of the obstructive lesion than balloon angioplasty

A balloon-expandable (Palmaz-Schatz) stainless steel stent was utilized following balloon angioplasty (PTRA) to determine if the obstructive lesion, using quantitative methods (automated measuring the diameter stenosis, and transstenotic peak systolic and mean pressure gradients), was significantly further reduced or abolished. Hemodynamic transstenotic gradient and stenoses measurements were made during 21 renal artery stenting procedures; prior and following PTRA, and subsequent to stent deployment. The stent sizes placed in the renal arteries were 5 mm (19%), 6 mm (67%), and 7 mm (14%). The results were as follows: [table: see text] The balloon-expandable (Palmaz-Schatz) stent significantly further reduced, and in fact effectively abolished, the obstructive renal artery lesion in comparison to balloon angioplasty (PTRA). The stent's effectiveness with regard lesion recurrence, maintenance, and preservation of renal function; cure or improved management of hypertension; and survival will be determined by careful clinic follow-up.

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.

Treatment of long coronary artery narrowings with long angioplasty balloon catheters

Balloon angioplasty of long coronary artery narrowings has been associated with a lower rate of acute success, and a higher rate of acute complications and restenosis than that observed for short narrowings. Angioplasty catheters with longer length balloons (30 and 40 mm) are now available, and the objective of this study was to determine the acute and long-term success for patients with long coronary artery narrowings treated with these longer balloons. All patients with long narrowings (> or = 10 mm) treated with long balloons at 1 institution over a 1-year period were identified (93 narrowings in 89 patients), and acute and long-term outcomes were carefully documented. Procedural success (residual stenosis < or = 50%) was 97%. Abrupt closure occurred in 6% and major dissection in 11% of narrowings. Clinical success (procedural success without in-hospital death, bypass surgery or myocardial infarction) was achieved in 90% of patients. Repeat catheterization was performed in 61 patients (76% of those eligible), and restenosis was found in 50 to 55%, depending on the definition used. The treatment of long coronary artery narrowings using angioplasty catheters with longer balloons leads to high rates of acute success. However, there is a high rate of restenosis. New interventional devices for long lesions should be compared with long balloons in a randomized controlled trial.

Prospective analysis of possible myocardial damage or hemolysis occurring as a result of prolonged autoperfusion angioplasty in humans

OBJECTIVES

The purpose of this study was to further explore the procedural safety of prolonged (15-min) dilation using an autoperfusion coronary angioplasty balloon by assessing the degree of myocardial damage or hemolysis, if any, occurring as a result of the procedure.

BACKGROUND

Prolonged balloon inflation periods may be beneficial during percutaneous transluminal coronary angioplasty. The duration of standard balloon angioplasty is often limited by the occurrence of myocardial ischemia due to loss of anterograde blood flow. Autoperfusion angioplasty allows continued myocardial perfusion during balloon inflation and has previously been shown to reduce but not totally eliminate acute myocardial ischemia during prolonged (up to 15 min) balloon inflation. The risk of intravascular hemolysis as a result of autoperfusion angioplasty has not yet been fully delineated.

METHODS

Sixty-two consecutive patients (76% men; mean age 58 years) undergoing elective percutaneous transluminal coronary angioplasty of a single lesion were studied. Serial electrocardiographic and creatine kinase MB isoenzyme data were examined to detect evidence of myocardial damage. Tests for hemolysis (plasma free hemoglobin, serum haptoglobin and serum lactate dehydrogenase) were obtained in the 1st 24 consecutive patients.

RESULTS

Inflation time was 14 +/- 4 min (mean +/- SD) and the procedure was successful (less than or equal to 50% residual lesion stenosis) in 59 patients (95%). Electrocardiographic evidence of myocardial infarction (greater than 1 mm persistent ST segment depression, greater than 1 mm ST segment elevation or new Q waves) was not observed in any patient. Cardiac enzyme assays were within the normal range in all patients. No evidence of hemolysis was found in the 24 consecutive patients studied.

CONCLUSIONS

We conclude that prolonged autoperfusion angioplasty can be performed in patients without clinical evidence of myocardial damage or hemolysis.

Coronary angioplasty performed with gradual and prolonged inflation using a perfusion balloon catheter: procedural success and restenosis rate

The results of routine coronary angioplasty using gradual and prolonged balloon inflation with a perfusion balloon catheter were evaluated. One hundred forty patients were treated with inflation of the balloon to 6 atm over 3 minutes, with a median inflation time of 15 minutes. The procedural success rate (residual stenosis less than or equal to 50%) was 99%. In-hospital major complications occurred in five patients (3.6%), with one patient experiencing a periprocedural infarction, three patients requiring bypass surgery for abrupt closure, and one patient dying after elective bypass surgery following previous successful angioplasty of a culprit lesion. The restenosis rate in the 117 patients with angiographic follow-up (87% of those eligible) was 42%. Thus gradual and prolonged inflation using a perfusion balloon catheter resulted in a high procedural success rate and a restenosis rate similar to that reported in large studies of patients treated with standard angioplasty. These results warrant further study using a prospective randomized trial design.

Comparison of angiographic center and local site analysis of PTCA results in a multicenter angioplasty-restenosis trial. The M Heart Group

We compared three methods of coronary stenosis (S) sizing in a multihospital PTCA restenosis trial: visual analysis by independent observers, single point caliper measurements, and quantitative coronary angiography (QCA). Cine films from 50 patients were submitted from the clinical site to the quantitative angiographic center, where visual analysis and computer quantitation were performed. Regression analysis revealed a correlation coefficient of .857 for caliper vs. QCA (p less than .0001) and .876 for visual observation vs. QCA (p less than .0001). No significant differences were found between any of the 3 methods for pre- or post-PTCA stenosis values. However, QCA yielded smaller PTCA changes in stenosis severity than either caliper or visual observation (p less than .05). Both caliper and visual methods correlated well with QCA in assessing stenosis size pre- and post-PTCA. Trained observers can visually assess lesion severity with accuracy approaching QCA. QCA is likely to be less expensive when compared to visual analysis by three experienced observers and should be the method used for estimating the results of PTCA in clinical trials.

Intravascular ultrasound in coronary atherosclerosis: a new approach to clinical assessment

Intravascular ultrasound evaluation of the coronary arteries by means of a selective coronary catheter attached to an ultrasound unit has afforded precise depiction of coronary lumen diameter and area at the level of the catheter tip. The arterial wall at this level can be evaluated for lipid, fibrous tissue, calcification, wall dissections, and intraluminal thrombi. The technique has the advantage over coronary angioscopy and angiography in that it does not require infusions or injections to allow visualization, and it has the ability to depict the inside of the arterial wall. The current disadvantages include the inability to visualize the vessel segments distal to the catheter tip. Three-dimensional reconstruction techniques allow depiction of the segment of the artery traversed by the catheter tip. The use of Doppler ultrasound imaging provides information on coronary flow velocities through coronary obstructions. Intravascular ultrasound images may provide information that complements the coronary arteriogram and may have an impact on patient care and clinical investigation strategies.

Outcome after prolonged balloon inflations of greater than 20 minutes for initially unsuccessful percutaneous transluminal coronary angioplasty

Prolonged balloon inflation with or without autoperfusion techniques is a common initial approach to major dissection or abrupt occlusion after percutaneous transluminal coronary angioplasty (PTCA). To assess such a strategy in the setting of unsuccessful angioplasty, 40 patients who underwent prolonged balloon inflations of greater than 20 minutes between January and July of 1991 after initially unsuccessful angioplasty were studied. These patients (median age 59 years) underwent PTCA for progressive or unstable angina (16[40%]), symptomatic or asymptomatic residual stenosis after myocardial infarction (10[25%]), acute myocardial infarction (3[8%]), stable angina (3[8%]), reinfarction (2[5%]), and other indications (6[15%]). The significant stenoses were primarily in the proximal and midportions of the right coronary (53%), left anterior descending (30%) and left circumflex (17%) coronary arteries. Before prolonged balloon inflation, the longest single inflation was 11 +/- 6 minutes and the total time of all inflations was 17 +/- 8 minutes (mean +/- standard deviation). Stenosis was reduced from 91 +/- 9 to 68 +/- 16% before prolonged inflation. After prolonged balloon inflation of 30 +/- 9 minutes, the residual stenosis was 47 +/- 21% (p = 0.0001 vs value before prolonged inflation). Furthermore, improvements in the appearance of filling defects or dissections, or both, occurred in 19 patients (48%). Procedural success was obtained in 32 of 40 patients (80%). Coronary bypass grafting was performed in 8 patients (20%): 4 after unsuccessful PTCA (3 emergently) and 4 electively after initially successful PTCA. Although 5 patients had creatine kinase-MB elevations greater than 20 IU/liter after the procedure, only 1 sustained a Q-wave myocardial infarction. There were no deaths in the hospital.(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy and reproducibility of visual coronary stenosis estimates using information from multiple observers

The reliability of visual estimation of severity of coronary artery stenosis may be improved using data from multiple independent observers. Data were collected from the results of a video format examination used on an experimental basis in 1987 by the American Board of Internal Medicine to test 61 candidates for certification in cardiovascular diseases. Twenty arteriographic cases were presented in a standardized format. Each artery was viewed in multiple projections including angled views. Each view was shown in both real time and slow motion, and each case was seen twice in its entirety. The observers rated stenosis severity on a four-point scale ranging from 1-4. A two-way repeated measures analysis of variance was performed on the tabulated results, yielding variance components for the arteriographic data (signal), the differences among observers, and the observer by case interaction (both considered noise). These components then allowed calculation of 68 and 95% confidence intervals, the signal-to-noise ratio, and the reproducibility coefficient for any number of observers. When a single observer was considered, reproducibility was low, with 95% confidence intervals of +/- 0.9 points, corresponding to approximately +/- 22% diameter stenosis. However, when data of three observers were averaged, the 95% confidence interval decreased to +/- 0.52 points (13% stenosis), signal-to-noise ratio rose to 12.2, and reproducibility coefficient was 0.92. Relatively small increments in these values were noted when data from a fourth or fifth observer were added. In comparison to a computer-assisted quantitative method, 86% accuracy was found for the results of averaged subjective determinations of stenosis severity.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphologic change in coronary artery stenosis with the Medtronic Wiktor stent: initial results from the core laboratory for quantitative angiography

The purpose of this study was to assess the early changes in stenosis geometry after implantation of the Medtronic Wiktor stent in human coronary arteries. Morphologic changes were evaluated by quantitative coronary angiography using automated edge detection. The hemodynamic significance of the morphologic changes were assessed by the calculation of the theoretical pressure drop across the dilated and stented stenosis derived from the Poiseuile and turbulent resistances assuming a coronary blood flow of either 0.5, 1, or 3 ml/sec. Fifty patients were studied before and immediately after stent implantation. The stented coronary artery was the left anterior descending artery in 26 patients, the circumflex artery in eight patients, and the right coronary artery in 16 patients. Stent implantation resulted in an additional increase in the minimal luminal cross-sectional area and minimal luminal diameter of the dilated vessel without changing the curvature of the stenosis. Furthermore, there was a significant reduction of the "plaque area." This was associated with a normalization of the calculated resistances to flow and pressure drop across the stenosis. To a minimal extent, recoil (0.1 +/- 0.36 mm) was observed after stent implantation.

Effect of the degree of effort on exercise echocardiography for the detection of restenosis after coronary artery angioplasty

To determine whether the accuracy of exercise echocardiography is affected by the degree of effort during exercise, we examined 101 patients who had 6 months earlier undergone successful coronary artery angioplasty, with resting and immediate postexercise echocardiography and same-day coronary angiography. A positive exercise echocardiographic response was defined as the development of a new or worsening wall motion abnormality postexercise, compared with resting wall motion. Significant coronary disease (greater than 50% diameter stenosis) was present in 48 patients, 38 of whom had single-vessel disease and 10 of whom had two-vessel disease. Exercise echocardiography correctly identified 32 patients with significant disease (sensitivity 67%) and 44 patients without significant disease (specificity 83%). The effect of the degree of exercise effort on the sensitivity and specificity of the test was evaluated by three criteria; (1) the percentage of maximum predicted heart rate (MHR), (2) the duration of exercise (DUR), and (3) the double product (DP). To determine the influence of the degree of effort upon sensitivity and specificity, the effort criteria were compared between patients with true positive (TP) tests to those with false negative tests (FN), and in patients with true negative (TN) tests compared with those with false positive (FP) tests. No significant differences were detected in MHR, DUR, or DP between TP versus FN patients or between TN versus FP patients. These results indicate that for symptom-limited exercise echocardiography in postangioplasty patients, neither sensitivity nor specificity is significantly affected by the degree of effort during exercise.

Correlation of quantitative angiographic parameters with changes in left ventricular diastolic function after angioplasty of the left anterior descending coronary artery

This study evaluates the changes in left ventricular (LV) diastolic filling after percutaneous transluminal coronary angioplasty and the relation of such changes to quantitative angiographic measurements of the severity of coronary narrowings. Pulsed Doppler echocardiographic measurements were performed in 40 patients with single left anterior descending artery narrowing before, and 10 and 30 days after angioplasty. Minimal luminal diameter and percent diameter stenosis of coronary lesions were measured by computer-assisted quantitation. The ratio of early to late diastolic flow velocities (E/A ratio), time velocity integral of early diastolic filling period (Ei) and the ratio of early and late diastolic filling periods (Ei/Ai ratio) increased gradually after angioplasty. Minimal luminal diameter correlated significantly with the percent changes in E/A ratio (r = 0.59 at 10 days, r = 0.57 at 30 days), Ei (r = 0.53 at 10 days, r = 0.55 at 30 days) and Ei/Ai ratio (r = 0.41 at 10 days, r = 0.49 at 30 days). Percent diameter stenosis showed overall weaker correlations than minimal diameter with the percent changes in E/A ratio (r = 0.39 at 10 days, r = 0.32 at 30 days) and Ei (r = 0.38 at 10 days, r = 0.31 at 30 days). Thus, LV diastolic filling improves serially after coronary angioplasty in patients with 1-vessel disease. The magnitude of improvement in diastolic filling correlates better with minimal luminal diameter than percent diameter stenosis. Therefore, minimal luminal diameter is a better predictor of changes in Doppler transmitral flow parameters after angioplasty than percent diameter stenosis.

Coronary restenosis: what have we learned from angiography?

Coronary restenosis remains a major problem for interventional cardiology not only by virtue of its frequency, but also because of the current inability to prevent it. Symptomatic status and non-invasive evaluation have been used to study restenosis, but both lack specificity and sensitivity, particularly in patients with multivessel disease. Angiography remains the reference standard. Several arbitrary definitions have been used, some related to visual estimates of coronary stenosis and others to quantitative angiographic techniques. In another approach, linear modeling is used to assess minimal luminal diameter of lesions on restudy. Although angiographic studies have been essential in the study of restenosis, questions concerning the underlying mechanism and pathophysiology remain. The development of animal models that closely resemble human restenosis should allow evaluation of pathophysiologic mechanisms and development of new strategies to prevent the problem.

Quantification of rate of coronary artery disease progression by a new method of angiographic analysis

To assess the rate and variability of atherostenosis progression in patients with coronary artery disease at baseline angiography, we used a simplified quantitative method of analysis to study single angiograms in 54 patients and paired angiograms in 29 patients. All discrete lesions were identified, then traced and digitized to determine lumen diameter (LD), and summed to give the total LD; the differences in LD for paired angiograms were summed to give total stenosis change (TSC). The following results were obtained: Correlation between LD measured by our method and LD determined by the Brown/Dodge method was excellent (r = 0.99, N = 54). There also was a high correlation between interobserver (r = 0.98, N = 54) and intraobserver (r = 0.99, N = 54) findings. Short-term TSC (N = 9, angiograms paired at less than 1 week) was negligible (0.03 +/- 0.38 mm). Long-term (N = 20, angiograms paired at 0.6 to 4.3 years) total LD differed significantly from baseline total LD (4.1 +/- 2.5 mm vs 6.0 +/- 3 mm; p less than 0.001), and TSC (2.0 +/- 1.3 mm) in long-term patients differed significantly from TSC in short-term patients (p less than 0.001). These results show that true coronary disease progression occurring over 1 to 4 years can be distinguished from intraobserver, interobserver, and interstudy variability by means of a simplified method and provide approximate rates and variability of progression. These results will be useful for power calculations in therapeutic trials aimed at slowing progression. Further prospective studies with the use of this method appear indicated.

Evaluation of human panelists in assessing coronary atherosclerosis

The Cholesterol Lowering Atherosclerosis Study, a randomized, angiographic clinical trial, has demonstrated the beneficial effect of niacin/colestipol therapy on coronary and femoral atherosclerosis. The primary outcome was a panel-determined consensus score evaluating global coronary changes determined angiographically at 2 years. This article presents an evaluation of interreader agreement in independently assessing the status of native coronary arteries and overall coronary condition. Parameters include 1) identification of the presence of lesions and lesion changes; 2) estimation of lesion severity (percent stenosis) and amount of change in lesion severity; and 3) global assessment of change in coronary status. Readers independently agreed on 1) presence of lesions (82%) and change in lesions (51%); 2) percent stenosis +/- 10% (76%) and change in stenosis +/- 10% (81%); and 3) global assessment of change in coronary status within one step (96%). Results of these analyses may be useful in effectively designing angiographic trials that use a panel of human evaluators as well as computerized methods for angiographic interpretation.

Edge detection versus densitometry for assessing coronary stenting quantitatively

The optimal method used to analyze quantitatively the immediate angiographic results of coronary stenting in the coronary arteries has not been studied. Accordingly, minimal luminal cross-sectional area was determined by 2 methods, edge detection and densitometry, in 19 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) and then coronary stent implantation for symptomatic coronary stenoses. The correlation coefficient, 0.73 before angioplasty, decreased to 0.59 after coronary angioplasty and then increased to 0.83 after stent implantation. The mean differences between edge detection and densitometric determinations of minimal luminal cross-sectional area were 0.31 +/- 0.51 mm2 before PTCA, -0.38 +/- 1.22 mm2 after angioplasty and 0.35 +/- 0.79 mm2 after coronary stenting. It is concluded that, although the correlation and variability in the measurement of minimal luminal cross-sectional area between edge detection and densitometry deteriorate after PTCA, they are improved after stenting, probably because of smoothing of the vessel contours by the stent and remodeling of the stented segment into a more circular configuration. Therefore, in the stented coronary artery, edge detection and densitometry are equally acceptable methods of analysis.

Prognostic value of radionuclide angiography in medically treated patients with coronary artery disease. A comparison with clinical and catheterization variables

To evaluate the usefulness of multiple measures from rest and exercise radionuclide angiography (RNA) in predicting cardiovascular death and cardiovascular events (death or nonfatal myocardial infarction) and to assess the prognostic usefulness of the RNA relative to clinical and catheterization data, we studied 571 stable patients with symptomatic coronary artery disease who had upright rest/exercise first-pass RNA within 3 months of catheterization and were medically treated. With a median follow-up of 5.4 years, 90 patients have died from cardiovascular causes, and 147 patients have either died or suffered a nonfatal myocardial infarction. Using the Cox regression model and a preselected group of RNA variables, the most important RNA predictor of mortality was exercise ejection fraction (chi 2 = 81, p less than 0.00001). Neither rest ejection fraction nor the change in ejection fraction from rest to exercise contributed additional predictive information. Two other RNA study variables, the change in heart rate from rest to exercise and rest end-diastolic volume index, did contribute additional prognostic information to the exercise ejection fraction (chi 2 = 23, p less than 0.0001). Compared with noninvasive clinical data (history, physical examination, electrocardiogram, and chest radiograph), RNA variables were considerably more predictive of mortality (chi 2 = 71 [clinical variables] versus chi 2 = 104 [RNA]). Remarkably, the strength of the relation of RNA variables with mortality was equivalent to that of the set of catheterization variables previously demonstrated in our large angiographic population to be prognostically important (chi 2 = 104 [RNA] versus chi 2 = 102 [catheterization variables]). The RNA contained 84% of the information provided by clinical and catheterization descriptors combined. Furthermore, the RNA contributed significant additional prognostic information to the clinical and catheterization data (chi 2 = 13.6, p = 0.0035). For cardiovascular events, the relative prognostic usefulness of the RNA was similar, although relations with this outcome were generally weaker. Descriptors from the rest/exercise RNA exhibit a powerful relation with long-term outcomes and can be useful in defining risk, even when clinical and catheterization data are available.