P598T1 mapping and myocardial extracellular volume assessed by cardiac magnetic resonance in diabetic patients with stable coronary artery disease

Background

T1 mapping is a quantitative technique of cardiac magnetic resonance (CMR) increasingly used for characterization of the myocardium. Type 2 diabetes mellitus (T2DM) may impact myocardial tissue structure, however studies that assessed this association using non-invasive methods have conflicting results.

Purpose

We sought to compare the tissue characteristics of the non-infarcted myocardium of patients with and without diabetes with multivessel CAD.

Methods

Patients with stable multivessel CAD and preserved left ventricular ejection fraction (LVEF), included in the MASS V trial, underwent contrast-enhanced CMR before revascularization procedures. Patients were stratified according to the T2DM diagnosis at baseline. Values of myocardial native T1, post-contrast T1 and extracellular volume fraction (ECV) were compared between diabetic and non-diabetic patients. Only myocardial tissue without late gadolinium enhancement were assessed.

Results

Of 155 patients studied, 67 (43%) were diabetic and 88 (57%) non-diabetic. Baseline characteristics were similiar between groups (age 70±10 vs 69±11; 69% vs 68% males; LVEF 65±13 vs 67±9). Mean Syntax score was 21.2±8.5 and 20.4±8.5 (p=0.52) in diabetic and non-diabetic, respectively. Myocardial native T1 values showed no diference in diabetic and non-diabetic (1013±67.9 vs 1015±61.4, p=0.72). However, in diabetic patients values of post-contrast T1 were significantly lower (482.2±43.8 vs 499.4±47.2, p=0.024) and ECV were higher (29.62±6.61 vs 27.08. ± 4.22, p=0.004). Multivariable analyses adjusted for age, sex, BMI, hypertension and Syntax score showed no differences in the results.

Figure1

Conclusion

In this study, T2DM was associated with higher ECV and lower post-contrast T1 values in the myocardial tissue. These findings suggest an increase in the myocardial intersticial matrix in patients with diabetes and stable multivessel CAD.

P1832Myocardial injury assessed by T1 mapping after on-pump and off-pump coronary artery bypass grafting. a pre-specified analysis of mass V trial

Background

Myocardial structural damage may occur during coronary artery bypass grafting (CABG) surgery and is identified by the significant release of cardiac biomarkers. However, the evidence of these structural myocardial changes after CABG by current imaging methods remains unknown. To evaluate myocardial structure, we used the T1 mapping of cardiac magnetic resonance (CMR) before and after on-pump and off-pump CABG.

Methods

Patients with multivessel coronary artery disease and preserved ventricular function were included and underwent on or off-pump CABG. CMR and T1 mapping were performed using the MOLLI technique (modified Look-Locker inversion-recovery). Values of native T1 and extracellular volume fraction (ECV) were compared before and after on and off-pump procedures.

Results

Of 110 eligible patients, 34 were excluded due to the presence of new late enhancement or edema. Of 76 patients remained, 32 (42%) underwent on-pump (Group A) and 44 (58%) off-pump CABG (Group B). All baseline characteristics were similar between groups, besides the Syntax Score that was higher in Group A (25 × 21, p=0.002). For group A, native T1 before and after procedures was 1013 ms (998–1043) and 1004 ms (793–1048), p=0.19, and ECV was 26.4 (23.9–27.6) and 31.2 (27.6–33.9), p<0.001. For group B, native T1 before and after procedures was 1015 ms (970–1044) and 992 ms (867–1051), p=0.003, and ECV 27.5 (25.3–29.9) and 30.3 (26.5–34.3), p=0.02. The comparison of native T1 difference before and after procedures between groups A and B was not significant (Delta T1 −9.8 (−102 to 51.8) × −25.4 (−119 to 51,2), p=0.87. However, the difference of ECV between groups was statistically significant (ECV Delta 3.8 (2.2 to 7.1) × 1.3 (−1.1 to 4.9), p=0.039, respectively, for groups A and B.

Figure 1

Conclusion

In this sample, T1 mapping identified significant myocardial structural changes in both surgical revascularization procedures. Additionally, a marked myocardial injury generated by ECV changes were observed after on-pump CABG.

P1835Application of SYNTAX score I, II and residual SYNTAX as predictors of long-term clinical outcomes after coronary artery bypass grafting

Background

The evaluation of coronary disease by SYNTAX score I (SSI) is used to grade coronary complexity. Following SSI, two other scores were developed: SYNTAX score II (SSII) and residual SYNTAX score (rSS). Nevertheless, there is still a lack of evidence about the prognostic significance of these scores among patients undergoing CABG.

Purpose

Our aim was to evaluate the relation of the SSI, SSII and rSS score with outcomes in a long-term follow-up after elective CABG.

Methods

This is a single center, registry-based study. Baseline SSI was calculated from patients undergoing CABG by interventional cardiologists. SSI results were considered as usual: <23, 23–32 and >32. SSII and rSRR were then calculated and categorized in tertiles: <21.4, 21.4–29.4 and >29.4 for SSII and 0, 1–5 and >5 for rSS. Primary outcome was a composite of overall death, myocardial infarction, additional revascularization, or stroke (MACCE).

Results

Data were obtained from 559 patients. Median follow-up was 6 years (IQR: 4.9–9.8) and 170 events were documented. The Kaplan-Meier curves (figure 1) showed significant differences of MACCE in higher SSI, SSII and rSS (p=0.039, 0.033, <0.001 respectively). After multivariate adjustment, rSS, ejection fraction (EF) and age were found to be independent predictors of MACCE (p<0.001, 0.034 and 0.006, respectively).

Figure 1

Conclusion

In this sample SSI, II and residual were associated with the occurrence of events. However, just the rSS remained an independent predictor of MACCE together with age and EF.

Association Between Stress Testing-Induced Myocardial Ischemia and Clinical Events in Patients With Multivessel Coronary Artery Disease

IMPORTANCE

The long-term prognostic implications of myocardial ischemia documented during stress testing in patients with multivessel coronary artery disease (CAD) are unclear.

OBJECTIVE

To assess whether documented stress testing-induced myocardial ischemia is associated with major adverse cardiovascular events or ventricular function changes in patients with stable multivessel CAD.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study was conducted using data from a single-center randomized clinical trial (Medicine, Angioplasty, or Surgery Study [MASS] II) to examine the association of myocardial ischemia documented during stress testing at baseline with cardiovascular events and ventricular function changes during follow-up. Participants were previously randomized (May 1, 1995, to May 31, 2000) to medical therapy, percutaneous coronary intervention with bare metal stents, or coronary artery bypass grafting. Event-free survival was estimated by the Kaplan-Meier method, and multivariable Cox regression models were calculated to assess the association between ischemia and the primary composite end point. The vital status was determined on February 28, 2011. Data were analyzed from February 1, 2016, to April 1, 2017.

MAIN OUTCOMES AND MEASURES

Cardiovascular events (overall mortality, myocardial infarction, and revascularization for refractory angina) were tracked from the time of randomization to the end of the 10-year follow-up (mean [SD] duration, 11.4 [4.3] years). Myocardial ischemia was assessed at baseline and at 1-year intervals by exercise stress testing, and ventricular function (left ventricular ejection fraction) was assessed by echocardiography at baseline and after 10 years. Patients with documented ischemia were compared with those without ischemia regarding the outcomes and changes in ventricular function.

RESULTS

Of 611 participants, 535 underwent exercise stress testing at baseline: 270 with documented ischemia and 265 without. Of these 535 patients, 373 (69.7%) were men, and the mean (SD) age for the entire cohort was 59.7 (9.2) years. No association was found between the presence of ischemia at baseline and survival free of combined cardiovascular events (hazard ratio, 1.00; 95% CI, 0.80-1.27; P = .95) after multivariable adjustment that included CAD initial randomized treatments. In addition, among 320 patients who underwent echocardiographic evaluation, the slight decline in left ventricular ejection fraction after 10 years was similar in both groups (median [SD] difference, -4.9% [18.7%] vs -6.6% [20.0%], respectively, for groups with and without ischemia; P = .97).

CONCLUSIONS AND RELEVANCE

In this study, regardless of the therapeutic strategy applied, the presence of documented myocardial ischemia did not appear to be associated with an increased occurrence of major adverse cardiovascular events or changes in ventricular function in patients with multivessel CAD during a long-term follow-up.

Clinical significance of chronic myocardial ischemia in coronary artery disease patients

Myocardial ischemia is considered the cornerstone of the treatment of patients with coronary artery disease (CAD). Although the deleterious effects of myocardial infarction, the maximum expression of ischemia, have been extensively studied and described, the clinical effects of chronic, documented myocardial ischemia are not completely clarified. The first studies that compared therapies for coronary disease focused on the presence of anatomical features and assessed ischemia based on the interpretation of the findings of obstructive atherosclerotic lesions. They suggested that revascularization interventions did not confer any clinical advantage over medical therapy (MT), in terms of cardiac or overall death. Other retrospective studies that were dedicated to assessing the impact of documented stress-induced ischemia on cardiovascular outcomes have suggested a prognostic impact of chronic ischemia. However, this has been questioned in recent studies. Moreover, the previous understanding that chronic ischemia could lead to worsening of ventricular function was not confirmed in a recent study. Thus, the prognostic significance of stress-induced ischemia has been questioned. Regarding treatment options, although some previous analyses have suggested that interventional therapies would reduce cardiovascular events in CAD patients with documented ischemia, recent post-hoc studies and metanalysis have shown distinct results. In this review article, the authors discuss myocardial ischemia, the different responses of the myocardium to ischemic insults, ischemic preconditioning, and the main findings of recent studies about the clinical aspects and treatment of patients with chronic, documented myocardial ischemia.

Behavior of Ultrasensitive C-Reactive Protein in Myocardial Revascularization with and without Cardiopulmonary Bypass

Objective

To analyze the inflammation resulting from myocardial revascularization techniques with and without cardiopulmonary bypass, based on ultrasensitive C-reactive protein (US-CRP) behavior.

Methods

A prospective non-randomized clinical study with 136 patients was performed. Sixty-nine patients were enrolled for Group 1 (on-pump coronary artery bypass - ONCAB) and 67 patients were assigned to Group 2 (off-pump coronary artery bypass - OPCAB). All study participants had blood samples collected for analysis of glucose, triglycerides, creatinine, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and creatinephosphokinase (CPK) in the preoperative period. The samples of creatinephosphokinase MB (CKMB), troponin I (TnI) and US-CRP were collected in the preoperative period and at 6, 12, 24, 36, 48 and 72 hours after surgery. We also analyzed the preoperative biological variables of each patient (age, smoking, diabetes mellitus, left coronary trunk lesion, body mass index, previous myocardial infarction, myocardial fibrosis). All angiographically documented patients with >70% proximal multiarterial stenosis and ischemia, documented by stress test or classification of stable angina (class II or III), according to the Canadian Cardiovascular Society, were included. Reoperations, combined surgeries, recent acute myocardial infarction, recent inflammatory disease, deep venous thrombosis or recent pulmonary thromboembolism, acute kidney injury or chronic kidney injury were not included.

Results

Correlation values between the US-CRP curve and the ONCAB group, the treatment effect and the analyzed biological variables did not present expressive results. Laboratory variables were evaluated and did not correlate with the applied treatment (P>0.05).

Conclusion

The changes in the US-CRP at each moment evaluated from the postoperative period did not show any significance in relation to the surgical technique applied.

Long-Term Survival Following Multivessel Revascularization in Patients With Diabetes: The FREEDOM Follow-On Study

BACKGROUND

The FREEDOM (Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease) trial demonstrated that for patients with diabetes mellitus (DM) and multivessel coronary disease (MVD), coronary artery bypass grafting (CABG) is superior to percutaneous coronary intervention with drug-eluting stents (PCI-DES) in reducing the rate of major adverse cardiovascular and cerebrovascular events after a median follow-up of 3.8 years. It is not known, however, whether CABG confers a survival benefit after an extended follow-up period.

OBJECTIVES

The purpose of this study was to evaluate the long-term survival of DM patients with MVD undergoing coronary revascularization in the FREEDOM trial.

METHODS

The FREEDOM trial randomized 1,900 patients with DM and MVD to undergo either PCI with sirolimus-eluting or paclitaxel-eluting stents or CABG on a background of optimal medical therapy. After completion of the trial, enrolling centers and patients were invited to participate in the FREEDOM Follow-On study. Survival was evaluated using Kaplan-Meier analysis, and Cox proportional hazards models were used for subgroup and multivariate analyses.

RESULTS

A total of 25 centers (of 140 original centers) agreed to participate in the FREEDOM Follow-On study and contributed a total of 943 patients (49.6% of the original cohort) with a median follow-up of 7.5 years (range 0 to 13.2 years). Of the 1,900 patients, there were 314 deaths during the entire follow-up period (204 deaths in the original trial and 110 deaths in the FREEDOM Follow-On). The all-cause mortality rate was significantly higher in the PCI-DES group than in the CABG group (24.3% [159 deaths] vs. 18.3% [112 deaths]; hazard ratio: 1.36; 95% confidence interval: 1.07 to 1.74; p = 0.01). Of the 943 patients with extended follow-up, the all-cause mortality rate was 23.7% (99 deaths) in the PCI-DES group and 18.7% (72 deaths) in the CABG group (hazard ratio: 1.32; 95% confidence interval: 0.97 to 1.78; p = 0.076).

CONCLUSIONS

In patients with DM and MVD, coronary revascularization with CABG leads to lower all-cause mortality than with PCI-DES in long-term follow-up. (Comparison of Two Treatments for Multivessel Coronary Artery Disease in Individuals With Diabetes [FREEDOM]; NCT00086450).

Comparative cost-effectiveness of surgery, angioplasty, or medical therapy in patients with multivessel coronary artery disease: MASS II trial

Background

The costs for treating coronary artery disease (CAD) are high worldwide. We performed a prespecified analyses of cost-effectiveness of three therapeutic strategies for multivessel CAD.

Methods

From May 1995 to May 2000, a total of 611 patients were randomly assigned to coronary artery bypass graft (CABG), n = 203; percutaneous coronary intervention (PCI), n = 205; or medical treatment (MT), n = 203. This cost analysis study was based on the perspective of the Public Health Care System. Initial procedural and follow-up costs for medications, cardiology examinations, and hospitalizations for complications were calculated after randomization. Life-years and quality-adjusted life years (QALYs) were used as effectiveness measures. Incremental cost-effectiveness ratios (ICER) were obtained by using nonparametric bootstrapping methods with 5000 resamples.

Results

Initial procedural costs were lower for MT. However, the subsequent 5-year cumulative costs were lower for CABG. Compared with baseline, the three treatment options produced significant improvements in QALYs. After 5 years, PCI and CABG had better QALYs results compared with MT. The ICER results favored CABG and PCI, and favored PCI over CABG in 61% of the drawings. On the other hand, sensitivity analysis showed MT as the preferred therapy compared with CABG and PCI, in the analysis considering higher costs.

Conclusions

At 5-year follow-up, the three treatment options yielded improvements in quality of life, with comparable and acceptable costs. However, despite higher initial costs, the comparison of cost-effectiveness after 5 years of follow-up among the three treatments showed both interventions (CABG and PCI) to be cost-effective strategies compared with MT.Trial registration ISRCTN, ISRCTN66068876, Registered 06/10/1994, http://www.controlled-trials.com/ISRCTN66068876.

Ten-Year Follow-Up of Off-Pump and On-Pump Multivessel Coronary Artery Bypass Grafting: MASS III

It was a randomized trial, and 308 patients undergoing revascularization were randomly assigned: 155 to off-pump coronary artery bypass (OPCAB) and 153 to on-pump coronary artery bypass (ONCAB). End points were freedom from death, myocardial infarction, revascularization, and cerebrovascular accidents. The rates for 10-year, event-free survival for ONCAB versus OPCAB were 69.6% and 64%, (hazard ratio [HR]: 0.88; 95% confidence interval [CI] 0.86-1.02; P = .41), respectively. Adjusted Cox proportional hazard ratio was similar (HR: 0.92; 95% CI 0.61-1.38, P = .68). A difference occurred between the duration of OPCAB and ONCAB, respectively (4.9 ± 1.5 vs 6.6 ± 1.1 h, P < .001). Statistical differences occurred between OPCAB and ONCAB in the length of intensive care unit (ICU) stay (20 ± 2.5 vs 48 ± 10 hours, P < .001), time to extubation (5.5 ± 4.2 vs 10.2 ± 3.5 hours, P < .001), hospital stay (6.7 ± 1.4 vs 9.2 ± 1.3 days, P < .001), higher incidence of atrial fibrillation (AF; 33 vs 5 patients, P < .001), and blood requirements (46 vs 64 patients, P < .001). Grafts per patient was higher in ONCAB (3.15 vs 2.55 grafts, P < .001). No difference existed between the groups in primary composite end points at 10-year follow-up. Although OPCAB surgery was related to a lower number of grafts and higher incidence of AF, it had no effects related to long-term outcomes.