Predicting outcome in the COURAGE trial (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation): coronary anatomy versus ischemia

Appropriateness ratings of percutaneous coronary intervention in Japan and its association with the trend of noninvasive testing

OBJECTIVES

The aim of this study was to evaluate the appropriateness of percutaneous coronary intervention (PCI) in Japan and clarify the association between trends of pre-procedural noninvasive testing and changes in appropriateness ratings.

BACKGROUND

Although PCI appropriateness criteria are widely used for quality-of-care improvement, they have not been validated internationally. Furthermore, the correlation of appropriateness ratings with implementation of newly developed noninvasive testing is unclear.

METHODS

We assigned an appropriateness rating to 11,258 consecutive PCIs registered in the Japanese Cardiovascular Database according to appropriateness use criteria developed in 2009 (AUC/2009) and the 2012 revised version (AUC/2012). Trends of pre-procedural noninvasive testing and appropriateness ratings were plotted; logistic regression was performed to identify inappropriate PCI predictors.

RESULTS

In nonacute settings, 15% of PCIs were rated inappropriate under AUC/2009, and this percent increased to 30.7% under AUC/2012 criteria. This was mostly because of the focused update of AUC, in which the patients were newly classified as inappropriate if they lacked proximal left anterior descending lesions and did not undergo pre-procedural noninvasive testing. However, these cases were simply not rated under AUC/2009. The amount of inappropriate PCIs increased over 5 years, proportional to the increase in coronary computed tomography angiography use. Use of coronary computed tomography angiography was independently associated with inappropriate PCIs (odds ratio: 1.33; p = 0.027).

CONCLUSIONS

In a multicenter, Japanese PCI registry, approximately one-sixth of nonacute PCIs were rated as inappropriate under AUC/2009, increasing to approximately one-third under the revised AUC/2012. This significant gap may reflect a needed shift in appropriateness recognition of methods for noninvasive pre-procedural evaluation of coronary artery disease.

Meta-analysis of trials on mortality after percutaneous coronary intervention compared with medical therapy in patients with stable coronary heart disease and objective evidence of myocardial ischemia

Outcomes of percutaneous coronary intervention (PCI) versus medical therapy (MT) in the management of stable ischemic heart disease (SIHD) remain controversial, with some but not all studies showing improved results in patients with ischemia. We sought to elucidate whether PCI improves mortality compared to MT in patients with objective evidence of ischemia (assessed using noninvasive imaging or its invasive equivalent). We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing PCI to MT in patients with SIHD. To maintain a high degree of specificity for ischemia, studies were only included if ischemia was defined on the basis of noninvasive stress imaging or abnormal fractional flow reserve. The primary outcome was all-cause mortality. We identified 3 RCTs (Effects of Percutaneous Coronary Interventions in Silent Ischemia After Myocardial Infarction II, Fractional Flow Reserve versus Angiography for Multivessel Evaluation 2, and a substudy of the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation trial) enrolling a total of 1,557 patients followed for an average of 3.0 years. When compared with MT in this population of patients with objective ischemia, PCI was associated with lower mortality (hazard ratio 0.52, 95% confidence interval 0.30 to 0.92, p=0.02). There was no evidence of study heterogeneity or bias among included trials. In this meta-analysis of published RCTs, PCI was shown to have a mortality benefit over MT in patients with SIHD and objective assessment of ischemia using noninvasive imaging or its invasive equivalent. In conclusion, this study provides insight into the management of a higher-risk SIHD population that is the focus of the ongoing International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial.

The myth of the "vulnerable plaque": transitioning from a focus on individual lesions to atherosclerotic disease burden for coronary artery disease risk assessment

The cardiovascular science community has pursued the quest to identify vulnerable atherosclerotic plaque in patients for decades, hoping to prevent acute coronary events. However, despite major advancements in imaging technology that allow visualization of rupture-prone plaques, clinical studies have not demonstrated improved risk prediction compared with traditional approaches. Considering the complex relationship between plaque rupture and acute coronary event risk suggested by pathology studies and confirmed by clinical investigations, these results are not surprising. This review summarizes the evidence supporting a multifaceted hypothesis of the natural history of atherosclerotic plaque rupture. Managing patients at risk of acute coronary events mandates a greater focus on the atherosclerotic disease burden rather than on features of individual plaques.

HOMA-IR is associated with significant angiographic coronary artery disease in non-diabetic, non-obese individuals: a cross-sectional study

Insulin resistance is a major component of metabolic syndrome, type 2 Diabetes Mellitus (T2DM) and coronary artery disease (CAD). Although important in T2DM, its role as a predictor of CAD in non-diabetic patients is less studied. In the present study, we aimed to evaluate the association of HOMA-IR with significant CAD, determined by coronary angiography in non-obese, non-T2DM patients. We also evaluate the association between 3 oral glucose tolerance test (OGTT) based insulin sensitivity indexes (Matsuda, STUMVOLL-ISI and OGIS) and CAD. We conducted a cross-sectional study with 54 non-obese, non-diabetic individuals referred for coronary angiography due to suspected CAD. CAD was classified as the "anatomic burden score" corresponding to any stenosis equal or larger than 50 % in diameter on the coronary distribution. Patients without lesions were included in No-CAD group. Patients with at least 1 lesion were included in the CAD group. A 75 g oral glucose tolerance test (OGTT) with measurements of plasma glucose and serum insulin at 0, 30, 60, 90 and 120 min was obtained to calculate insulin sensitivity parameters. HOMA-IR results were ranked and patients were also categorized into insulin resistant (IR) or non-insulin resistant (NIR) if they were respectively above or below the 75th percentile (HOMA-IR > 4.21). The insulin sensitivity tests results were also divided into IR and NIR, respectively below and above each 25th percentile. Chi square was used to study association. Poisson Regression Model was used to compare prevalence ratios between categorized CAD and IR groups.

RESULTS

Fifty-four patients were included in the study. There were 26 patients (48 %) with significant CAD. The presence of clinically significant CAD was significant associated with HOMA-IR above p75 (Chi square 4.103, p = 0.0428) and 71 % of patients with HOMA-IR above p75 had significant CAD. Subjects with CAD had increased prevalence ratio of HOMA-IR above p75 compared to subjects without CAD (PR 1.78; 95 % CI 1.079-2.95; p = 0.024). Matsuda index, Stumvoll-ISI and OGIS index were not associated with significant CAD. We concluded that, in patients without diabetes or obesity, in whom a coronary angiography study is indicated, a single determination of HOMA-IR above 4.21 indicates increased risk for clinical significant coronary disease. The same association was not seen with insulin sensitivity indexes such as Matsuda, Stunvoll-ISI or OGIS. These findings support the need for further longitudinal research using HOMA-IR as a predictor of cardiovascular disease.

Cardiac CT: atherosclerosis to acute coronary syndrome

Coronary computed tomographic angiography (CCTA) is a robust non-invasive method to assess coronary artery disease (CAD). Qualitative and quantitative assessment of atherosclerotic coronary stenosis with CCTA has been favourably compared with invasive coronary angiography (ICA) and intravascular ultrasound (IVUS). Importantly, it allows the study of preclinical stages of atherosclerotic disease, may help improve risk stratification and monitor the progressive course of the disease. The diagnostic accuracy of CCTA in the assessment of coronary artery bypass grafts (CABG) is excellent and the constantly improving technology is making the evaluation of stents feasible. Novel techniques are being developed to assess the functional significance of coronary stenosis. The excellent negative predictive value of CCTA in ruling out disease enables early and safe discharge of patients with suspected acute coronary syndromes (ACS) in the Emergency Department (ED). In addition, CCTA is useful in predicting clinical outcomes based on the extent of coronary atherosclerosis and also based on individual plaque characteristics such as low attenuation plaque (LAP), positive remodelling and spotty calcification. In this article, we review the role of CCTA in the detection of coronary atherosclerosis in native vessels, stented vessels, calcified arteries and grafts; the assessment of plaque progression, evaluation of chest pain in the ED, assessment of functional significance of stenosis and the prognostic significance of CCTA.

Global coronary flow reserve is associated with adverse cardiovascular events independently of luminal angiographic severity and modifies the effect of early revascularization

BACKGROUND

Coronary flow reserve (CFR), an integrated measure of focal, diffuse, and small-vessel coronary artery disease (CAD), identifies patients at risk for cardiac death. We sought to determine the association between CFR, angiographic CAD, and cardiovascular outcomes.

METHODS AND RESULTS

Consecutive patients (n=329) referred for invasive coronary angiography after stress testing with myocardial perfusion positron emission tomography were followed (median 3.1 years) for cardiovascular death and heart failure admission. The extent and severity of angiographic disease were estimated with the use of the CAD prognostic index, and CFR was measured noninvasively by positron emission tomography. A modest inverse correlation was seen between CFR and CAD prognostic index (r=-0.26; P<0.0001). After adjustment for clinical risk score, ejection fraction, global ischemia, and early revascularization, CFR and CAD prognostic index were independently associated with events (hazard ratio for unit decrease in CFR, 2.02; 95% confidence interval, 1.20-3.40; P=0.008; hazard ratio for 10-U increase in CAD prognostic index, 1.17; 95% confidence interval, 1.01-1.34; P=0.032). Subjects with low CFR experienced rates of events similar to those of subjects with high angiographic scores, and those with low CFR or high CAD prognostic index showed the highest risk of events (P=0.001). There was a significant interaction (P=0.039) between CFR and early revascularization by coronary artery bypass grafting, such that patients with low CFR who underwent coronary artery bypass grafting, but not percutaneous coronary intervention, experienced event rates comparable to those with preserved CFR, independently of revascularization.

CONCLUSIONS

CFR was associated with outcomes independently of angiographic CAD and modified the effect of early revascularization. Diffuse atherosclerosis and associated microvascular dysfunction may contribute to the pathophysiology of cardiovascular death and heart failure, and impact the outcomes of revascularization.

Nonobstructive coronary artery disease and risk of myocardial infarction

IMPORTANCE

Little is known about cardiac adverse events among patients with nonobstructive coronary artery disease (CAD).

OBJECTIVE

To compare myocardial infarction (MI) and mortality rates between patients with nonobstructive CAD, obstructive CAD, and no apparent CAD in a national cohort.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of all US veterans undergoing elective coronary angiography for CAD between October 2007 and September 2012 in the Veterans Affairs health care system. Patients with prior CAD events were excluded.

EXPOSURES

Angiographic CAD extent, defined by degree (no apparent CAD: no stenosis >20%; nonobstructive CAD: ≥1 stenosis ≥20% but no stenosis ≥70%; obstructive CAD: any stenosis ≥70% or left main [LM] stenosis ≥50%) and distribution (1, 2, or 3 vessel).

MAIN OUTCOMES AND MEASURES

The primary outcome was 1-year hospitalization for nonfatal MI after the index angiography. Secondary outcomes included 1-year all-cause mortality and combined 1-year MI and mortality.

RESULTS

Among 37,674 patients, 8384 patients (22.3%) had nonobstructive CAD and 20,899 patients (55.4%) had obstructive CAD. Within 1 year, 845 patients died and 385 were rehospitalized for MI. Among patients with no apparent CAD, the 1-year MI rate was 0.11% (n = 8, 95% CI, 0.10%-0.20%) and increased progressively by 1-vessel nonobstructive CAD, 0.24% (n = 10, 95% CI, 0.10%-0.40%); 2-vessel nonobstructive CAD, 0.56% (n = 13, 95% CI, 0.30%-1.00%); 3-vessel nonobstructive CAD, 0.59% (n = 6, 95% CI, 0.30%-1.30%); 1-vessel obstructive CAD, 1.18% (n = 101, 95% CI, 1.00%-1.40%); 2-vessel obstructive CAD, 2.18% (n = 110, 95% CI, 1.80%-2.60%); and 3-vessel or LM obstructive CAD, 2.47% (n = 137, 95% CI, 2.10%-2.90%). After adjustment, 1-year MI rates increased with increasing CAD extent. Relative to patients with no apparent CAD, patients with 1-vessel nonobstructive CAD had a hazard ratio (HR) for 1-year MI of 2.0 (95% CI, 0.8-5.1); 2-vessel nonobstructive HR, 4.6 (95% CI, 2.0-10.5); 3-vessel nonobstructive HR, 4.5 (95% CI, 1.6-12.5); 1-vessel obstructive HR, 9.0 (95% CI, 4.2-19.0); 2-vessel obstructive HR, 16.5 (95% CI, 8.1-33.7); and 3-vessel or LM obstructive HR, 19.5 (95% CI, 9.9-38.2). One-year mortality rates were associated with increasing CAD extent, ranging from 1.38% among patients without apparent CAD to 4.30% with 3-vessel or LM obstructive CAD. After risk adjustment, there was no significant association between 1- or 2-vessel nonobstructive CAD and mortality, but there were significant associations with mortality for 3-vessel nonobstructive CAD (HR, 1.6; 95% CI, 1.1-2.5), 1-vessel obstructive CAD (HR, 1.9; 95% CI, 1.4-2.6), 2-vessel obstructive CAD (HR, 2.8; 95% CI, 2.1-3.7), and 3-vessel or LM obstructive CAD (HR, 3.4; 95% CI, 2.6-4.4). Similar associations were noted with the combined outcome.

CONCLUSIONS AND RELEVANCE

In this cohort of patients undergoing elective coronary angiography, nonobstructive CAD, compared with no apparent CAD, was associated with a significantly greater 1-year risk of MI and all-cause mortality. These findings suggest clinical importance of nonobstructive CAD and warrant further investigation of interventions to improve outcomes among these patients.

Prognostic role of restenosis in 10 004 patients undergoing routine control angiography after coronary stenting

AIM

Routine control angiography is a valuable tool with high-sensitivity in detecting restenosis after coronary stenting. However, the prognostic role of restenosis is still controversial. We investigated the impact of restenosis on 4-year mortality in patients undergoing routine control angiography after coronary stenting.

METHODS AND RESULTS

All the patients undergoing successful implantation of coronary stents for de novo lesions from 1998 to 2009 and routine control angiography after 6-8 months at two centres in Munich, Germany were studied. Restenosis was defined as diameter stenosis ≥50% in the in-segment area at follow-up angiography. The primary outcome was 4-year mortality. The study included 10 004 patients with 15 004 treated lesions. Restenosis was detected in 2643 (26.4%) patients. Overall, there were 702 deaths during the follow-up. Of these, 218 deaths occurred among patients with restenosis and 484 deaths occurred among patients without restenosis [unadjusted hazard ratio: HR: 1.19; (95% confidence interval CI: 1.02-1.40); P = 0.03]. The Cox proportional hazards model adjusting for other variables identified restenosis as an independent correlate of 4-year mortality [HR: 1.23; (95% CI: 1.03-1.46); P = 0.02]. Other independent correlates of 4-year mortality were age [for each 10-year increase, HR: 2.34; (95% CI: 2.12-2.60); P < 0.001], diabetes mellitus [HR: 1.68; (95% CI: 1.41-1.99); P < 0.001], current smoking habit [HR: 1.39; (95% CI: 1.09-1.76); P = 0.01], and left ventricular ejection fraction [for each 5% decrease, HR: 1.39; (95% CI: 1.31-1.48); P < 0.001].

CONCLUSIONS

In this large cohort of patients, the presence of restenosis at follow-up angiography after coronary stenting was predictive of 4-year mortality. Whether routine control angiography after coronary stenting is beneficial and influences outcomes should be evaluated by properly designed randomized trials.

Extent of coronary and myocardial disease and benefit from surgical revascularization in ischemic LV dysfunction [Corrected]

BACKGROUND

Patients with ischemic left ventricular dysfunction have higher operative risk with coronary artery bypass graft surgery (CABG). However, those whose early risk is surpassed by subsequent survival benefit have not been identified.

OBJECTIVES

This study sought to examine the impact of anatomic variables associated with poor prognosis on the effect of CABG in ischemic cardiomyopathy.

METHODS

All 1,212 patients in the STICH (Surgical Treatment of IsChemic Heart failure) surgical revascularization trial were included. Patients had coronary artery disease (CAD) and ejection fraction (EF) of ≤35% and were randomized to receive CABG plus medical therapy or optimal medical therapy (OMT) alone. This study focused on 3 prognostic factors: presence of 3-vessel CAD, EF below the median (27%), and end-systolic volume index (ESVI) above the median (79 ml/m(2)). Patients were categorized as having 0 to 1 or 2 to 3 of these factors.

RESULTS

Patients with 2 to 3 prognostic factors (n = 636) had reduced mortality with CABG compared with those who received OMT (hazard ratio [HR]: 0.71; 95% confidence interval [CI]: 0.56 to 0.89; p = 0.004); CABG had no such effect in patients with 0 to 1 factor (HR: 1.08; 95% CI: 0.81 to 1.44; p = 0.591). There was a significant interaction between the number of factors and the effect of CABG on mortality (p = 0.022). Although 30-day risk with CABG was higher, a net beneficial effect of CABG relative to OMT was observed at >2 years in patients with 2 to 3 factors (HR: 0.53; 95% CI: 0.37 to 0.75; p<0.001) but not in those with 0 to 1 factor (HR: 0.88; 95% CI: 0.59 to 1.31; p = 0.535).

CONCLUSIONS

Patients with more advanced ischemic cardiomyopathy receive greater benefit from CABG. This supports the indication for surgical revascularization in patients with more extensive CAD and worse myocardial dysfunction and remodeling. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).

A score to quantify coronary plaque vulnerability in high-risk patients with type 2 diabetes: an optical coherence tomography study

Background

Patients with type 2 diabetes are at a high risk for acute cardiovascular events, which usually arise from the rupture of a vulnerable coronary lesion characterized by specific morphological plaque features. Thus, the identification of vulnerable plaques is of utmost clinical importance in patients with type 2 diabetes. However, there is currently no scoring system available to identify vulnerable lesions based on plaque characteristics. Thus, we aimed to characterize the diagnostic value of optical coherence tomography (OCT) - derived lesion characteristics to quantify plaque vulnerability both as individual parameters and when combined to a score in patients with type 2 diabetes.

Methods

OCT was performed in the coronary culprit lesions of 112 patients with type 2 diabetes. The score, which quantifies plaque vulnerability, was defined as the predicted probability that a lesion is the cause for an acute coronary syndrome (ACS) (vs. stable angina (SAP)) based on its specific plaque morphology.

Results

Multivariable logistic regression analysis demonstrated that plaque vulnerability was independently predicted by the minimal fibrous cap thickness overlying a lesion’s lipid core (odds ratio (OR) per 10 μm 0.478, p = 0.002), the medium lipid arc (OR per 90° 13.997, p < 0.001), the presence of macrophages (OR 4.797, p = 0.015) and the lipid plaque length (OR 1.290, p = 0.098).

Receiver-operating-characteristics (ROC) analyses demonstrated that these parameters combined to a score demonstrate an excellent diagnostic efficiency to identify culprit lesions of patients with ACS (vs. SAP, AUC 0.90, 95% CI 0.84-0.96).

Conclusion

This is the first study to present a score to quantify lesion vulnerability in patients with type 2 diabetes. This score may be a valuable adjunct in decision-making and useful in guiding coronary interventions.

Imaging plaques to predict and better manage patients with acute coronary events

Culprit lesions of patients, who have had an acute coronary syndrome commonly, are ruptured coronary plaques with superimposed thrombus. The precursor of such lesions is an inflamed thin-capped fibroatheroma. These plaques can be imaged by means of invasive techniques, such as intravascular ultrasound (and derived techniques), optical coherence tomography, and near-infrared spectroscopy. Often these patients exhibit similar (multiple) plaques beyond the culprit lesion. These remote plaques can be assessed noninvasively by computed tomographic angiography and MRI and also using invasive imaging. The detection of these remote plaques is not only feasible but also in natural history studies have been associated with clinical coronary events. Different systemic pharmacological treatments have been studied (mostly statins) with modest success and, therefore, newer approaches are being tested. Local treatment for such lesions is in its infancy and larger, prospective, and randomized trials are needed. This review will describe the pathological and imaging findings in culprit lesions of patients with acute coronary syndrome and the assessment of remote plaques. In addition, the pharmacological and local treatment options will be reviewed.