Summaries of Late-breaking Science Presentations at the 2018 American Heart Association meeting in Chicago, IL

Summaries of Late-breaking Science Presentations at the 2018 American Heart Association meeting in Chicago, IL

Summaries of Late-breaking Science Presentations at the 2018 American Heart Association meeting in Chicago, IL

 By Heather Nelson Cortes, PhD and Kevin C Maki, PhD

 Dapagliflozin and Cardiovascular Events in the DECLARE-TIMI 58 Trial

The Dapagliflozin Effect on Cardiovascular Events—Thrombolysis in Myocardial Infarction 58 (DECLARE-TIMI 58) Trial was designed to assess the safety and efficacy of dapagliflozin (10 mg/d), a selective sodium-glucose cotransporter (SGLT)-2 inhibitor, in the reduction of cardiovascular events in patients with type 2 diabetes mellitus.  This was a phase 3b, randomized, double-blinded, placebo-controlled trial in 17,160 patients ≥40 y of age with type 2 diabetes and either cardiovascular disease (CVD) or multiple CVD risk factors.  The primary efficacy endpoints were major adverse cardiovascular events (MACE; defined as cardiovascular death, myocardial infarction or ischemic stroke) and a composite of heart failure hospitalization (HHF) or cardiovascular death.  Median follow-up was 4.5 y.  The results for the outcomes including the hazard ratios (HR) and 95% confidence intervals (CI) are shown in the table below.

 

Outcome

Dapagliflozin

(n = 8582)

Placebo

(n = 8578)

HR (95% CI)

p-value

 

Rate/1000 patient-y

 

 

MACE

22.6

24.2

0.93 (0.84 to 1.03)

0.17

CVD/HHF

12.2

14.7

0.83 (0.73 to 0.95)

0.005

HHF

6.2

8.5

0.73 (0.61 to 0.88)

Cardiovascular death

7.0

7.1

0.98 (0.82 to 1.17)

All-cause mortality

15.1

16.4

0.93 (0.82 to 1.04)

Renal composite1

10.8

14.1

0.76 (0.67 to 0.87)

1Renal outcome was described as a 40% decrease in estimated glomerular filtration rate to <60 mL/min/1.73 m2, end-stage renal disease or death from renal or cardiovascular cause.

 

Conclusion:  Compared to placebo, dapagliflozin was safe and reduced the composite of cardiovascular death or HHF, but did not significantly reduce the incidence of MACE.

 Reference:

Wiviott SD, Raz I, Bonaca MP, et al. Dapagliflozin and cardiovascular outcomes in type 2 diabetes. N Engl J Med. 2018; Epub ahead of print.

 

 

Ezetimibe and Cerebro- and Cardiovascular Events in the EWTOPIA Trial
The role of lipid-lowering therapy in elderly (≥75 y of age) Japanese men and women with elevated low-density lipoprotein cholesterol (LDL-C) levels, but no history of coronary artery disease had not been well studied previously.  The Ezetimibe Lipid Lowering Trial on Prevention of Atherosclerosis in 75 or Older (EWTOPIA 75) investigation was a prospective, multi-center, open-label, blinded endpoint, randomized controlled trial conducted between 2009-2016 in Japanese men and women whose LDL-C level was ≥140 mg/dL and who had one or more cardiovascular risk factors (diabetes, hypertension, smoking, low high-density lipoprotein cholesterol, high triglycerides, previous history of cerebral infarction or peripheral artery disease). 

The primary endpoint was MACE, defined as a composite of sudden cardiac death, myocardial infarction, coronary revascularization, and/or stroke.  Secondary outcomes included cardiac events, cerebrovascular events, and all-cause mortality.  Eligible patients were randomized to either an ezetimibe group (10 mg/d plus dietary counseling; n = 1716) or a control group (dietary counseling alone; n = 1695).  LDL-C levels were reduced significantly more among patients taking ezetimibe (from 161 to 120 mg/dL) compared to subjects in the control group (from 162 to 131 mg/dL) (p < 0.001 for interaction).  The results for the outcomes are shown in the table below.

 

Outcome

HR (95% CI)

p-value

MACE

0.66 (0.50 to 0.86)

0.002

Cardiac events

0.60 (0.37 to 0.98)

0.04

Cerebrovascular events

0.78 (0.55 to 1.11)

>0.05

All-cause mortality

1.09 (0.89 to 1.34)

 

Conclusions:  In an elderly (≥75 y) Japanese population, ezetimibe (10 mg/d) plus dietary counseling compared to dietary counseling alone for primary prevention (elevated LDL-C, no history of CVD), was shown to help prevent cerebro- and cardiovascular events. 

 References:

Kumbhani DJ.  Ezetimibe in prevention of cerebro- and cardiovascular events in middle- to high-risk, elderly (75 years old or over) patients with elevated LDL-cholesterol – EWTOPIA 75.   https://www.acc.org/latest-in-cardiology/clinical-trials/2018/11/08/22/56/ewtopia75#references-for-article.

Ouchi Y. Ezetimibe in prevention of cerebro- and cardiovascular events in middle-to high-risk, elderly (75 years old or over) patients with elevated LDL-cholesterol: a multicenter, randomized, controlled, open-label trial. Presented at AHA 2018. November 10, 2018. Chicago, IL.

 

 

The Cardiovascular Inflammation Reduction Trial (CIRT): Low Dose Methotrexate for the Prevention of Atherosclerotic Events
CIRT was a randomized, double-blind trial of low-dose methotrexate (LD-MTX; target dose 15-20 mg/week) or placebo in patients with a prior myocardial infarction or multi-vessel coronary disease who also had either type 2 diabetes or metabolic syndrome.  It was designed to investigate whether inhibiting inflammation with LD-MTX might provide a similar cardiovascular benefit to that shown previously by treatment with canakinumab, an anti-inflammatory agent.  At the outset of CIRT, the primary endpoint was a composite of nonfatal myocardial infarction, nonfatal stroke or cardiovascular death.  Towards the end of the trial, but before the trial was unblinded, hospitalization for unstable angina that led to urgent revascularization was added to the composite primary endpoint.

Eligible patients were randomly assigned to either LD-MTX (n = 2391) or placebo (n = 2395), and all patients also received 1 mg folate/day.  The trial was stopped after a median follow-up of 2.3 years (maximum 5.1 years) because it had crossed a pre-specified boundary for futility for both the original and final endpoints, and due to the lack of evidence for a reduction in C-reactive protein (CRP) with LD-MTX.  Median changes in inflammatory markers from enrollment to eight months in the LD-MTX and placebo groups, respectively, were 0.09 and 0.05 mg/L for CRP, -0.24 and -0.31 pg/mL for interleukin (IL)-1ß and 0.30 and 0.04 pg/mL for IL-6 (all p >0.05).  Results for the cardiovascular endpoints are shown below.

 

Outcome

LD-MTX

(n = 2391)

Placebo

(n = 2395)

HR (95% CI)

p-value

 

Rate/100 patient-y

 

 

Original MACE

3.46

3.43

1.01 (0.82 to 1.25)

0.91

Final MACE

4.13

4.31

0.96 (0.79 to 1.16)

0.67

Conclusions:  In patients with prior myocardial infarction or multivessel CVD with either type 2 diabetes or metabolic syndrome, LD-MTX did not reduce inflammatory markers or cardiovascular events when compared to placebo.

 Reference:

Ridker PM, Everett BM, Pradhan A, et al. Low-dose methotrexate for the prevention of atherosclerotic events. N Engl J Med. 2018; Epub ahead of print.

Photo by Aaron Bean

CVD-REAL Results Suggest that Cardiovascular Benefits of Sodium-Glucose Cotransporter-2 (SGLT-2) Inhibitors are, Indeed, Real

CVD-REAL

CVD-REAL Results Suggest that Cardiovascular Benefits of Sodium-Glucose Cotransporter-2 (SGLT-2) Inhibitors are, Indeed, Real

By Kevin C Maki, PhD

 Background

In 2015, the release of the Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME) trial results generated significant surprise and controversy.1 The investigators randomly assigned 7,020 patients with type 2 diabetes mellitus (T2D) to receive 10 or 25 mg/d of empagliflozin or placebo.  Empagliflozin is a sodium-glucose cotransporter-2 inhibitor that reduces renal reabsorption of glucose and sodium, thus increasing urinary losses and reducing the plasma glucose concentration.  The primary composite outcome was death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke in the pooled empagliflozin group compared with the placebo group.

The EMPA-REG OUTCOME results showed a 14% reduction (p = 0.04) in the primary outcome in the empagliflozin group.  Despite significant reductions in blood pressure, glycated hemoglobin and body weight, there were no differences between the groups in myocardial infarction or stroke.  However, there were substantial reductions (p ≤ 0.002) in death from cardiovascular causes (38%) and hospitalization for heart failure (35%).

More recently, the results from the Canagliflozin Cardiovascular Assessment Study (CANVAS) program were released in which data were pooled from two placebo-controlled studies of another SGLT-2 inhibitor, canagliflozin, involving 10,142 patients with T2D at high cardiovascular risk.2  The outcome for the primary composite, which was the same as that in EMPA-REG OUTCOME, showed that canagliflozin treatment was associated with a significant 14% reduction, a result that was essentially identical to that in the EMPA-REG OUTCOME study overall.  However, there were some differences between the results for individual components of the composite.

 

Outcome EMPA-REG OUTCOME (empagliflozin) CANVAS

(canagliflozin)

Hazard Ratio (95% Confidence Interval)
Primary Composite 0.86 (0.74-0.99) 0.86 (0.75-0.97)
Death from Cardiovascular Causes 0.62 (0.49-0.77) 0.87 (0.72-1.06)
Non-fatal Myocardial Infarction 0.87 (0.70-1.09) 0.85 (0.69-1.05)
Non-fatal Stroke 1.24 (0.92-1.67) 0.90 (0.71-1.15)
Hospitalization for Heart Failure 0.65 (0.50-0.85) 0.67 (0.52-0.87)
Death from Any Cause 0.68 (0.57-0.82) 0.87 (0.74-1.01)

The notable differences are for death from cardiovascular causes (38% reduction vs. non-significant 13% reduction) and death from any cause (32% reduction vs. non-significant 13% reduction), for which the results with empagliflozin appeared more favorable, and non-fatal stroke (non-significant 24% increase vs. non-significant 10% reduction), for which the results appeared more favorable for canagliflozin. Or course, such differences could easily be due to random variation, so additional studies are needed with these and other agents in the SGLT-2 inhibitor class.  Large-scale randomized, controlled clinical trials are expensive and time consuming, so it is useful to look at results in the real world for patients prescribed these medications in clinical practice.  Results from such investigations need to be viewed with caution because they are more susceptible to various types of bias and confounding than results from randomized trials.  Nevertheless, they can be useful for evaluating risks and benefits of drug therapies and to further evaluate hypotheses generated from clinical trial data, such as whether there are differences in cardiovascular outcomes between agents in the SGLT-2 inhibitor class.

Comparative Effectiveness of Cardiovascular Outcomes in New Users of SGLT-2 Inhibitors (CVD-REAL) Methods and Results3

Data were collected from medical claims in the US and several countries in the EU.  A propensity score was used to adjust for SGLT-2 inhibitor initiation.  Hazard ratios were calculated for hospitalization for heart failure, all-cause mortality, and incidence of either outcome among those taking SGLT-2 inhibitors compared with other glucose-lowering drugs (GLD).

Data were included for more than 300,000 patients, half of whom took an SGLT-2 inhibitor and half of whom took other GLDs.  Canagliflozin was the most commonly used SGLT-2 inhibitor (53% of exposure), followed by dapagliflozin (42% of exposure) and empagliflozin (5% of exposure).  Canagliflozin was the most commonly used SGLT-2 inhibitor in the US (76%), whereas dapagliflozin was the most commonly used in Europe (92%); 87% of subjects had no known cardiovascular disease at baseline.

Over 190,164 person-years of follow-up, hazard ratios for hospitalization for heart failure (0.61, 95% CI 0.51-0.73), death (0.49, 0.41-0.57) and either outcome (0.54, 0.48-0.60) were all significantly below the null, indicating that incidence rates for these outcomes were 39-51% lower for SGLT-2 inhibitors compared with other GLDs.  Sensitivity analyses were consistent with the main results, with no evidence of significant heterogeneity across type of SGLT-2 inhibitor or country.

Comment

The results of the CVD-REAL investigation support the hypothesis that use of the SGLT-2 inhibitor class reduces risks for heart failure and death in patients with T2D.  The mechanisms responsible for these benefits, which are generally confirmatory (significant reductions or trends) for those observed in the EMPA-REG OUTCOME and CANVAS trials, are not well understood.  The SGLT-2 inhibitor class does not differ markedly from other GLD classes regarding effects on glycemic control.  Additional research will be needed to elucidate mechanisms responsible, which may have implications for the application of this drug class to other high-risk groups who do not have T2D.

References:

  1. Zinman B, Wanner C, Lachin JM, et al. Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. N Engl J Med. 2015;373:2117-2128.
  2. Neal B, Perkovic V, Mahaffey KW, et al. Canagliflozin and cardiovascular and renal events in type 2 diabetes. 2017; Jun 12. [Epub ahead of print].
  3. Kosiborod M, Cavendar MA, Fu AZ, et al. Lower risk of heart failure and death in patients initiated on sodium-glucose cotransporter-2 inhibitors versus other glucose-lowering drugs: the CVD-REAL study (Comparative Effectiveness of Cardiovascular Outcomes in New Users of Sodium-Glucose Cotransporter-2 Inhibitors). Circulation. 2017;136:249-259.

 

 

 

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