Maximally tolerated guideline-directed medical therapy and barriers to optimization in patients with heart failure with reduced ejection fraction: the COAPT trial

Background

The COAPT trial of MitraClip therapy employed a central screening eligibility committee (CSEC) of heart failure (HF) experts to ensure the use of maximally tolerated guideline-directed medical therapy (GDMT) and systematically document intolerances in all potential patients prior to approval for randomization.

Purpose

To describe the percentage of GDMT classes, doses tolerated, predictors of intolerance, and specific intolerances limiting GDMT among patients approved for randomization by the CSEC.

Methods

We analyzed baseline use, dose, and intolerances of i) angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB) or angiotensin receptor neprilysin inhibitor (ARNI); ii) beta-blockers (BB); and iii) mineralocorticoid receptor antagonists (MRA) in the CSEC-approved COAPT population with HF with reduced ejection fraction (HFrEF; LVEF ≤40%). We analyzed variables associated with GDMT tolerance.

Results

In COAPT, 464 patients had HFrEF and complete screening medication information. Any dose of all 3, 2 or 1 GDMT classes were tolerated in 39%, 39% and 20% of patients respectively; only 2% of patients (n=9) could not tolerate any GDMT (Figure 1). BB were prescribed in the most (93%) patients followed by ACEI/ARB/ARNI (69%) and MRA (55%). Intolerances limiting each GDMT class differed, but hypotension and kidney dysfunction were most common (Figure 2). No patients tolerated goal doses of all 3 GDMT classes. For BB, only 32% tolerated ≥50% of the goal dose; while for ACEI/ARB/ARNI, no patients achieved goal doses, and only 1% tolerated ≥50% of the goal dose. For MRA, 86% of patients tolerated 25mg/day or less. Patients intolerant of BB were less likely to tolerate an ACEI/ARB/ARNI (OR 0.39, 95% CI 0.20–0.76; p=0.004) but not a MRA (p=0.21) compared with patients tolerating a low dose BB. Patients intolerant of MRA were less likely to tolerate ACEI/ARB/ARNI therapy (OR 0.37, 95% CI 0.25–0.57; p<0.0001) but not a BB (p=0.31) compared with patients tolerating MRA. Patients tolerating low dose ACEI/ARB/ARNI had a higher baseline mean eGFR (52±21 versus 40±21 ml/min/m2; p<0.0001) compared with patients intolerant of ACEI/ARB/ARNI. Likewise, patients tolerating MRA had a higher baseline mean eGFR (52±21 versus 42±21 ml/min/m2; p<0.0001) compared with patients intolerant of MRA.

Conclusion

In a contemporary trial in which HF specialists ensured GDMT optimization, many patients had medical intolerances prohibiting use of one or more GDMT classes, and few patients tolerated target doses. These findings indicate medical intolerances are the primary cause of low GDMT prescription rates in patients with moderate to severe HFrEF. Yet, use of GDMT in this very ill population was much better than “real world” registries of HFrEF suggesting that mandating careful CSEC review prior to study enrollment is important for clinical trials having the objective of randomizing a maximally treated patient cohort.

Funding Acknowledgement

Type of funding sources: None.

MetNet: Software to Build and Model the Biogenetic Lattice of Arabidopsis

MetNet (http://www.botany.iastate.edu/∼mash/metnetex/metabolicnetex.html) is publicly available software in development for analysis of genome-wide RNA, protein and metabolite profiling data. The software is designed to enable the biologist to visualize, statistically analyse and model a metabolic and regulatory network map of Arabidopsis, combined with gene expression profiling data. It contains a JAVA interface to an interactions database (MetNetDB) containing information on regulatory and metabolic interactions derived from a combination of web databases (TAIR, KEGG, BRENDA) and input from biologists in their area of expertise. FCModeler captures input from MetNetDB in a graphical form. Sub-networks can be identified and interpreted using simple fuzzy cognitive maps. FCModeler is intended to develop and evaluate hypotheses, and provide a modelling framework for assessing the large amounts of data captured by high-throughput gene expression experiments. FCModeler and MetNetDB are currently being extended to three-dimensional virtual reality display. The MetNet map, together with gene expression data, can be viewed using multivariate graphics tools in GGobi linked with the data analytic tools in R. Users can highlight different parts of the metabolic network and see the relevant expression data highlighted in other data plots. Multi-dimensional expression data can be rotated through different dimensions. Statistical analysis can be computed alongside the visual. MetNet is designed to provide a framework for the formulation of testable hypotheses regarding the function of specific genes, and in the long term provide the basis for identification of metabolic and regulatory networks that control plant composition and development.