Comparative-effectiveness of revascularization versus routine medical therapy for stable ischemic heart disease: a population-based study

Medical therapy versus percutaneous coronary intervention in ischemic heart disease: A cost-effectiveness analysis

Background: Ischemic heart disease is categorized into two acute and chronic groups, and its treatments include revascularization and medical therapy. The aim of this study is to evaluate the economic burden of medical therapy compared to percutaneous coronary intervention in ischemic heart disease.

Methods: This study has been done in two steps. The first was a systematic review and meta-analysis to measure the effectiveness of two interventions and the second step was a cost-effectiveness analysis from the perspective of society. The data analysis included a meta-analysis and the Markov cohort simulation. RewMan v5 and tree age software were utilized. Uncertainties related to the model parameters were evaluated using one-way and two-way sensitivity analyses.

Results: Regarding the effectiveness of interventions, the odd ratio of the quality of life in the medical therapy group (CI: 0.76-1.10) was 0.91 times the PCI group (p=0.34). This rate for mortality in medical therapy (CI: 0.52-9.68) was 2.23 times more than the PCI group; this result was not significant (p=0.02). In the cost-effectiveness analysis, the cost-effectiveness threshold was $ 16,482; ICER in increasing the QoL and reduction in the mortality rate was $ 25320.11 and $ 562.6691, respectively. Regarding the sensitivity analysis, the model was not sensitive in changing parameters in a specific domain.

Conclusion: According to this study, PCI is more cost-effective than medical therapy in the reduction of mortality rate and in the field of increasing quality of life. MT strategy is more cost-effective than the PCI. This study considers controversies regarding the most appropriate treatment for patients with ischemic heart disease that is helpful for health policymakers, cardiologists and health managers.

Comparing the effectiveness of revascularization interventions with medical therapy in patients with ischemic cardiomyopathy: A systematic review and meta-analysis

Background: Determining the effectiveness of cardiovascular interventions plays an important role in reimbursement decisions, health care pricing, and providing clinical guidance on the use of existing clinical technologies. This study aimed to review and analyze the effectiveness of revascularization interventions (CABG and PCI) compared to medical therapy in patients with ischemic cardiomyopathy.

Methods: Different databases were searched up to December 2017. The articles were selected based on inclusion and exclusion criteria. Quality of all studies was evaluated by Jadad score and relevant checklists. The I2 test was used to test heterogeneity. Also, to integrate the results of similar studies, meta-analysis was done using STATA software.

Results: A total of 18 studies were included. Based on the random effects model, the overall results of comparing the effectiveness of revascularization interventions with medical therapy were as follow: 38.94 [95% CI: 26.95-50.94, p<0.001, I² = 99.6%, p<0.001], [75.31, 95% CI: 74.06-76.57, p<0.001, I²= 88.8, p<0.001], and 75.76 [95% CI: 71.99-79.53, p<0.001, I2= 99.2, p<0.001] for cardiac mortality rate, quality of life, and 5-year survival, respectively. Also, in patient satisfaction index, revascularization interventions were shown to be more effective than medical therapy.

Conclusion: This study showed that revascularization interventions in all studied indices were more effective than medical therapy. Also, between revascularization interventions, PCI was more effective in cardiovascular mortality and 5-year survival than CABG in terms of quality of life. Moreover, CABG was more effective than PCI. In patient satisfaction index, the results of the 2 included studies were contradictory.

Variation in Revascularization Practice and Outcomes in Asymptomatic Stable Ischemic Heart Disease

OBJECTIVES

The aims of this study were to assess variation in revascularization of asymptomatic patients with stable ischemic heart disease, identify the predictors of variation, and determine if it was associated with clinical outcomes.

BACKGROUND

Management of stable ischemic heart disease in asymptomatic patients with obstructive coronary artery disease is controversial, potentially leading to practice variation.

METHODS

A retrospective observational cohort study was performed using population-based data from Ontario, Canada, in patients with asymptomatic stable ischemic heart disease and obstructive coronary artery disease. The cohort was divided on the basis of treatment strategy: revascularization or medical therapy. Hospitals were allocated into tertiles of their revascularization ratio. Outcomes included death and nonfatal myocardial infarction. Hierarchical logistic regression was used to assess the predictors of revascularization, with median odds ratios used to quantify variation. Proportional hazards models were used to determine the association between management strategy and outcomes.

RESULTS

The cohort included 9,897 patients, 47% treated with medical therapy and 53% with revascularization. Between hospitals, 2-fold variation existed in the ratio of revascularized to medically treated patients. However, the variation across hospitals was not explained by patient, physician, or hospital factors (median odds ratio in null model: 1.25; median odds ratio in full model: 1.31). Revascularization was associated with a hazard ratio of 0.81 (95% confidence interval: 0.69 to 0.96) for death and a hazard ratio of 0.58 (95% confidence interval: 0.46 to 0.73) for myocardial infarction, with this benefit consistent across tertiles of revascularization ratio.

CONCLUSIONS

Wide variation was observed in revascularization practice that was not explained by known factors. Despite this variation, a clinical benefit was observed with revascularization that was consistent across hospitals.

Elective Coronary Revascularization Procedures in Patients With Stable Coronary Artery Disease: Incidence, Determinants, and Outcome (From the CORONOR Study)

OBJECTIVES

The authors sought to describe the incidence, determinants, and outcome of elective coronary revascularization (ECR) in patients with stable coronary artery disease (CAD).

BACKGROUND

Observational data are lacking regarding the practice of ECR in patients with stable CAD receiving modern secondary prevention.

METHODS

The authors analyzed coronary revascularization procedures performed during a 5-year follow-up in 4,094 stable CAD outpatients included in the prospective multicenter CORONOR (Suivi d'une cohorte de patients COROnariens stables en région NORd-Pas-de-Calais) registry.

RESULTS

Secondary prevention medications were widely prescribed at inclusion (antiplatelet agents 96.4%, statins 92.2%, renin-angiotensin system antagonists 81.8%). A total of 481 patients underwent ≥1 coronary revascularization procedure (5-year cumulative incidences of 3.6% [0.7% per year] for acute revascularizations and 8.9% [1.8% per year] for ECR); there were 677 deaths during the same period. Seven baseline variables were independently associated with ECR: prior coronary stent implantation (p < 0.0001), absence of prior myocardial infarction (p < 0.0001), higher low-density lipoprotein cholesterol (p < 0.0001), lower age (p < 0.0001), multivessel CAD (p = 0.003), diabetes mellitus (p = 0.005), and absence of treatment with renin-angiotensin system antagonists (p = 0.020). Main indications for ECR were angina associated with a positive stress test (31%), silent ischemia (31%), and angina alone (25%). The use of ECR had no impact on the subsequent risk of death, myocardial infarction, or ischemic stroke (hazard ratio: 1.04; 95% confidence interval: 0.76 to 1.41).

CONCLUSIONS

These real-life data show that ECR is performed at a rate of 1.8% per year in stable CAD patients widely treated by secondary medical prevention. ECR procedures performed in patients without noninvasive stress tests are not rare. Having an ECR was not associated with the risk of ischemic adverse events.

Variations in Use of Optimal Medical Therapy in Patients With Nonobstructive Coronary Artery Disease: A Population-Based Study

BACKGROUND

There is a paucity of data on the need for optimal medical therapy (OMT) in nonobstructive coronary artery disease . We sought to understand if there was variation in the use of OMT between hospitals for patients with nonobstructive coronary artery disease, the factors associated with such variation, and its clinical consequences.

METHODS AND RESULTS

Using a population-level clinical registry in Ontario, Canada, we identified all patients >66 years undergoing coronary angiography for the indication of stable angina, who had nonobstructive coronary artery disease between November 1, 2010, and October 31, 2013. Hierarchical multivariable logistic models were developed to identify the factors associated with OMT use, with median odds ratio used to quantify the degree of variation between hospitals not explained by the modeled risk factors. Clinical outcomes of interest were all-cause mortality and rehospitalization, with follow-up until March 31, 2015. Our cohort consisted of 5413 patients, of whom 2554 (47.2%) were receiving OMT within 1 year. There was a 2-fold variation in OMT across hospitals (30.4%-61.8%). The variation between hospitals was fully explained by preangiography medication use (median odds ratio of 1.21 in the null model and 1.03 in the full model). There was no difference in risk-adjusted mortality (hazard ratio, 0.94; 95% confidence interval, 0.76-1.16); however, patients receiving OMT had a lower risk of all-cause hospital readmission (hazard ratio, 0.89; 95% confidence interval, 0.84-0.95).

CONCLUSIONS

There is wide variation in the use of OMT in patients with nonobstructive coronary artery disease, the major driver of which is differences in baseline medication use.

Cost-Effectiveness of Different Durations of Dual-Antiplatelet Use After Percutaneous Coronary Intervention

BACKGROUND

There is uncertainty regarding the optimal duration of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). Our goal was to evaluate the cost-effectiveness of different durations of DAPT.

METHODS

We created a probabilistic patient-level Markov microsimulation model to assess the discounted lifetime costs and quality-adjusted life years (QALYs) of short duration (3-6 months: short-duration group) vs standard therapy (12 months: standard-duration group) vs prolonged therapy (30-36 months: long-duration group) in patients undergoing PCI.

RESULTS

The majority of patients in the model underwent PCI for stable angina (47.1%) with second-generation drug-eluting stents (62%) and were receiving clopidogrel (83.6%). Short-duration DAPT was the most effective strategy (7.163 ± 1.098 QALYs) compared with standard-duration DAPT (7.161 ± 1.097 QALYs) and long-duration DAPT (7.156 ± 1.097 QALYs). However, the magnitude of these differences was very small. Similarly, the average discounted lifetime cost was CAN$24,859 ± $6533 for short duration, $25,045 ± $6533 for standard duration, and $25,046 ± $6548 for long duration. Thus, in the base-case analysis, short duration was dominant, being more effective and less expensive. However, there was a moderate degree of uncertainty, because short duration was the preferred option in only ∼ 55% of simulations at a willingness to pay threshold of $50,000.

CONCLUSIONS

Based on a stable angina cohort receiving clopidogrel with second-generation stents, a short duration of DAPT was marginally better. However, the differences are minimal, and decisions about duration of therapy should be driven by clinical data, patient risk of adverse events, including bleeding, and cardiovascular events.

Management of Chronic Total Coronary Occlusion in Stable Ischemic Heart Disease by Percutaneous Coronary Intervention Versus Coronary Artery Bypass Grafting Versus Medical Therapy

Coronary chronic total occlusions (CTOs) are found in approximately 20% of angiograms. We sought to assess the variation in the management of patients with CTOs and to compare the clinical outcomes of CTO lesions with those of non-CTO lesions. We conducted a population-based cohort study and included all patients with stable angina who underwent cardiac catheterization from October 1, 2012, to June 30, 2013, in Ontario, Canada. The primary outcome was a composite of mortality and hospitalization for myocardial infarction. A total of 7,864 patients were included, of whom 2,279 (29%) had a CTO. There were substantial differences in revascularization rates for patients with CTOs across hospitals in Ontario (44.9% to 94.1%). Revascularization was associated with improved outcomes in the overall cohort. Although the advantage of coronary artery bypass grafting over medical therapy was consistent in both patients with CTOs and patients without CTOs, the benefit of percutaneous coronary intervention (PCI) was limited to patients without CTOs (hazard ratio 0.56, 95% confidence interval 0.40- to 0.78), with no difference in patients with CTOs. The CTO lesion, however, was revascularized in few of the PCI cases (41.1%), with PCI limited to the non-CTO lesion in most patients.

Cardiovascular Screening for the Asymptomatic Patient with Diabetes: More Cons Than Pros

Diabetes mellitus is associated with an increased risk of coronary heart disease (CHD) morbidity and mortality. Although it frequently coexists with other cardiovascular disease (CVD) risk factors, it confers an increased risk for CVD events on its own. Coronary atherosclerosis is generally more aggressive and widespread in people with diabetes (PWD) and is frequently asymptomatic. Screening for silent myocardial ischaemia can be applied in a wide variety of ways. In nearly all asymptomatic PWD, however, the results of screening will generally not change medical therapy, since aggressive preventive measures, such as control of blood pressure and lipids, would have been already indicated, and above all, invasive revascularization procedures (either with percutaneous coronary intervention or coronary artery bypass grafting) have not been shown in randomized clinical trials to confer any benefit on morbidity and mortality. Still, unresolved issues remain regarding the extent of the underlying ischaemia that might affect the risk and the benefit of revascularization (on top of optimal medical therapy) in ameliorating this risk in patients with moderate to severe ischaemia. The issues related to the detection of coronary atherosclerosis and ischaemia, as well as the studies related to management of CHD in asymptomatic PWD, will be reviewed here.

Clinical Impact of Subsequent Depression in Patients With a New Diagnosis of Stable Angina: A Population-Based Study

BACKGROUND

Depression is prevalent among patients with myocardial infarction and is associated with a worse prognosis. However, little is known about its importance in patients with chronic stable angina. We conducted a retrospective population-based cohort study to determine the occurrence and predictors of developing depression in patients with a new diagnosis of chronic stable angina. In addition, we sought to understand its impact on subsequent clinical outcomes.

METHODS AND RESULTS

Our cohort included patients in Ontario, Canada, with stable angina based on obstructive coronary artery disease found on angiogram. Depression was ascertained by physician billing codes and hospital admissions diagnostic codes. We first developed multivariable Cox proportional hazards models to determine predictors of developing depression. Clinical outcomes of interest included all-cause mortality, admission for myocardial infarction, and subsequent revascularization. Using hierarchical multivariable Cox proportional hazards models with occurrence of depression as a time-varying variable to control for potential immortal time bias, we evaluated the impact of depression on clinical outcomes. Our cohort consisted of 22 917 patients. The occurrence of depression after diagnosis of stable chronic angina was 18.8% over a mean follow-up of 1084 days. Predictors of depression included remote history of depression, female sex, and more symptomatic angina based on Canadian Cardiovascular Society class. Patients who developed depression had a higher risk of death (hazard ratio 1.83, 95% confidence interval 1.62-2.07) and admission for myocardial infarction (hazard ratio 1.36, 95% confidence interval 1.10-1.67) compared with nondepressed patients.

CONCLUSIONS

Depression is common in patients with chronic stable angina and is associated with increased morbidity and mortality.

Relation between initial treatment strategy in stable coronary artery disease and 1-year costs in Ontario: a population-based cohort study

BACKGROUND

Cardiovascular disease is costly, and annual expenditures are projected to increase. Our objective was to examine the variation in patient-level costs and identify drivers of cost in patients with stable coronary artery disease.

METHODS

In this retrospective cohort study using administrative databases in Ontario, Canada, we identified all patients with stable coronary artery disease after index angiography between Oct. 1, 2008, and Sept. 30, 2011. We excluded patients with a myocardial infarction within 90 days before the index, with normal coronaries, or with mild coronary disease. We categorized hospitals into low, medium or high revascularization ratio centres. The primary outcome was cumulative 1-year health care costs. A hierarchical generalized linear model identified patient, physician and hospital characteristics associated with patient costs, with 2 main covariates of interest: treatment allocation (medical v. percutaneous coronary intervention v. coronary artery bypass grafting) and hospital revascularization ratio.

RESULTS

A total of 183 630 angiography procedures were performed in Ontario during the study period. The final cohort included 39 126 patients with stable coronary artery disease, of which 15 138 received medical treatment and 23 988 received revascularization. The mean 1-year cost was $24 026 (interquartile range $8235-$30 511). The mean costs for medical management and revascularization were $18 069 and $27 786, respectively. The strongest predictor of costs was revascularization (percutaneous coronary intervention: cost ratio 1.27, 95% CI [confidence interval] 1.24-1.31; coronary artery bypass grafting: cost ratio 2.62, 95% CI 2.53-2.71). Hospital revascularization ratio did not significantly affect costs. There was no significant interaction between treatment and revascularization ratio.

INTERPRETATION

Most health care costs were due to acute care hospital admissions, and costs were higher for patients undergoing revascularization than medical therapy. This study suggests that treatment decision has a substantial impact on health care resources.

Medical Therapy With Versus Without Revascularization in Stable Patients With Moderate and Severe Ischemia: The Case for Community Equipoise

All patients with stable ischemic heart disease (SIHD) should be managed with guideline-directed medical therapy (GDMT), which reduces progression of atherosclerosis and prevents coronary thrombosis. Revascularization is also indicated in patients with SIHD and progressive or refractory symptoms, despite medical management. Whether a strategy of routine revascularization (with percutaneous coronary intervention or coronary artery bypass graft surgery as appropriate) plus GDMT reduces rates of death or myocardial infarction, or improves quality of life compared to an initial approach of GDMT alone in patients with substantial ischemia is uncertain. Opinions run strongly on both sides, and evidence may be used to support either approach. Careful review of the data demonstrates the limitations of our current knowledge, resulting in a state of community equipoise. The ongoing ISCHEMIA trial (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) is being performed to determine the optimal approach to managing patients with SIHD, moderate-to-severe ischemia, and symptoms that can be controlled medically. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Medical Therapy and Coronary Revascularization for Patients With Stable Coronary Artery Disease and Unclassified Appropriateness Score

Although the appropriate use criteria incorporate common clinical scenarios for coronary revascularization, a significant proportion of patients with stable coronary artery disease (CAD) cannot be assigned an appropriateness score. Our objective was to characterize these patients and to evaluate whether coronary revascularization is associated with improved outcomes. A population-based cohort of patients aged ≥66 years, who underwent cardiac catheterization in Ontario, Canada, were included. Clinical characteristics were compared between patients with and without an appropriateness score. Clinical outcomes between coronary revascularization and medical therapy in patients with unclassified appropriateness score were compared using the inverse probability of treatment-weighted propensity method for confounder adjustment. Of the 19,228 patients with stable CAD, 11.2% (2,153 patients) were not assigned to an appropriateness score, mostly (92.9%) because of a lack of ischemic evaluation or a noninterpretable test. These patients were older, had higher rate of severe angina, and had more medical co-morbidities compared to patients with an appropriateness score. The 2-year rate of death or myocardial infarction in patients with unclassified appropriateness score was 15.3% in the revascularization group versus 20.7% in the medical therapy group. After propensity weighting, revascularization was associated with significantly lower hazard ratio (0.70; 95% confidence interval 0.61 to 0.79) for death or myocardial infarction compared with medical therapy. In conclusion, in patients aged ≥66 years with stable CAD and unclassified appropriateness score, revascularization is associated with improved outcomes.

Predictors and Outcomes of Routine Versus Optimal Medical Therapy in Stable Coronary Heart Disease

Although randomized studies have shown optimal medical therapy (OMT) to be as efficacious as revascularization in stable coronary heart disease (CHD), the application of OMT in routine practice is suboptimal. We sought to understand the predictors of receiving OMT in stable CHD and its impact on clinical outcomes. All patients with stable CHD based on coronary angiography from October 2008 to September 2011 were identified in Ontario, Canada. OMT was defined as concurrent use of β blocker, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, and statin. Aspirin use was not part of the OMT definition because of database limitations. Multivariable hierarchical logistic models identified predictors of OMT in the 12 months after angiography. Cox proportional hazard models with time-varying covariates for OMT and revascularization status examined differences in death and nonfatal myocardial infarction (MI). In these models, patients transitioned among 4 mutually exclusive treatment groups: no OMT and no revascularization, no OMT and revascularization, OMT and no revascularization, OMT and revascularization. Our cohort had 20,663 patients. Over a mean period of 2.5 years, 8.7% had died. Only 61% received OMT within 12 months. The strongest predictor of receiving OMT at 12 months was OMT before the angiogram (odds ratio 14.40, 95% confidence interval [CI] 13.17 to 15.75, p <0.001). Relative to no OMT and nonrevascularized patients, patients on OMT and revascularized had the greatest reduction in mortality (hazard ratio 0.52, 95% CI 0.45 to 0.60, p <0.001) and nonfatal MI (hazard ratio 0.74, 95% CI 0.64 to 0.84, p <0.001). In conclusion, our study highlights the low rate of OMT in stable CHD. Patients who received both OMT and revascularization achieved the greatest reduction in mortality and nonfatal MI.

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.

Clinical Outcomes of Early Repatriation for Patients With ST-Segment Elevation Myocardial Infarction: A Propensity-Matched Analysis

BACKGROUND

Because of limitations on hospital resources, patients with ST-elevation myocardial infarction (STEMI) who undergo successful primary percutaneous coronary intervention (PCI) are often repatriated to non-PCI centres. However, the safety of this practice is not clear. Our objective was to evaluate the safety of early repatriation of STEMI patients after PCI to a non-PCI centre, compared with ongoing treatment at the PCI centre.

METHODS

Consecutive STEMI patients, who received primary PCI at 1 of 4 PCI hospitals in Toronto, Canada between 2010 and 2012 were identified. Patients with shock or who died within 24 hours of presentation were excluded. Outcomes of interest were all-cause mortality and readmission for recurrent myocardial infarction (MI) at 1 year. To account for confounding because of the observational nature of our data, propensity score-matched pairs of patients who were repatriated vs nonrepatriated were identified.

RESULTS

Using the propensity score, 430 well matched pairs were identified, representing our cohort. There was no significant difference between repatriated and nonrepatriated groups in 1-year mortality (repatriated: 6.7%, nonrepatriated: 5.6%, hazard ratio, 1.18; 95% confidence interval, 0.69-2.03; P = 0.545). The 1-year readmission rates for MI were significantly greater for the repatriated group compared with the nonrepatriated group (repatriated: 12.1%; nonrepatriated: 5.8%; hazard ratio, 2.09; 95% confidence interval, 1.30-3.36; P = 0.002).

CONCLUSIONS

A strategy of early repatriation of STEMI patients was associated with a greater rate of readmission for MI. Our study raises questions regarding the safety of an early repatriation strategy that merit further research.