Claria MRI™ Quad CRT-D SureScan™ System has a suite of diagnostic and therapeutic algorithms that allow you to personalize CRT for your patient needs. We know that achieving optimal patient response to cardiac resynchronization therapy can be challenging. That is why we developed the EffectivCRT™ Diagnostic Feature to identify ineffective pacing, plus the EffectivCRT During AF Feature to automatically adjust pacing rates. Together with AdaptivCRT™ Feature and the VectorExpress™ 2.0 LV Automated Test, these features allow you to tailor therapy to improve patient outcomes.1-3

Claria MRI CRT-D is compatible with Attain™ Performa™ Advanced Quadripolar Leads, including three shape options for varying patient anatomies. 

AdaptivCRT Improves Patient Outcomes2,3,4,6,7

Clinical evidence shows that AdaptivCRT improves patient outcomes, compared to echo-optimized CRT,3,4,6-9 including:

  • 12% absolute improvement in CRT response in patients with normal AV conduction*
  • 44% reduction in unnecessary right ventricular pacing at six months
  • 46% reduction in device-detected atrial fibrillation (AF)
  • 59% odds reduction of 30-day heart failure (HF) readmission**
  • Patients who received >50% of adaptive LV pacing had a lower rate of death or HF hospitalizations compared to patients who received <50% adaptive LV pacing
* Percentage of patients improved in Packer Clinical Composite Score at 6-month follow-up. Clinical Composite Score is a composite measure of mortality, HF hospitalization, and symptomatic changes.
48 or more continuous hours of atrial fibrillation. 
** Readmissions following a HF hospitalization.

The Need for EffectivCRT

Device Diagnostics Overestimate Effective CRT Pacing: Results of OLÉ CRT Study5

Results of the Holter for Efficacy Analysis of CRT (OLÉ) Study indicate that the percent ventricular pacing reported in CRT devices does not always indicate effective pacing. The study evaluated LV electrograms that were recorded by 24-hour Holter monitors from 57 CRT patients and concluded that:9

  • Current device pacing diagnostics overestimate the amount of CRT pacing actually delivered
  • The average percent ventricular pacing was 94.8% and the percent effective pacing was 87.5% (p<0.001)
  • 18% of subjects had at least 3% loss of effective pacing

Verify Effective Pacing with the EffectivCRT Diagnostic

With EffectivCRT Diagnostic, you see not only the quantity of pacing, but also the quality of pacing, as demonstrated in the graph above.5 EffectivCRT Diagnostic provides information needed to identify and address the reasons behind suboptimal CRT delivery.5


EffectivCRT During AF Improves CRT Delivery

A prospective, randomized, multicenter crossover study demonstrated the ability of EffectivCRT™ during AF to increase effective CRT delivery by up to 15%. Study results showed:1

  • EffectivCRT During AF increased effective pacing from 81% to 88% (p<0.001)
  • Heart rate increased by 3 beats per minute, from 77 to 80 BPM (p<0.001)
  • Patients with baseline (<80%) paced received the greatest benefit


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  1. Mittal S. A novel algorithm increases effective left ventricular pacing during atrial fibrillation in patients undergoing cardiac resynchronization therapy: Primary results of the randomized CRTee Trial. Presented at ESC Congress 2016.
  2. Starling RC, Krum H, Bril S, et al. Impact of a novel adaptive optimization algorithm on 30-Day readmissions: Evidence from the Adaptive CRT Trial. JACC Heart Fail. July2015;3(7):565-572.
  3. Martin D, Lemke B, Aonuma K, et al. Clinical outcomes with adaptive cardiac resynchronization therapy: Long-term outcomes of the  Adaptive CRT Trial. HFSA Late Breakers. September 23, 2013.
  4. Martin DO, Lemke B, Birnie D, et al. Investigation of a novel algorithm for synchronized left-ventricular pacing and ambulatory optimization of cardiac resynchronization therapy. Heart Rhythm. November 2012;9(11):1807-1814.
  5. Hernandez-Madrid A, Facchin D, Klepfer RN, et al. Device pacing diagnostics overestimate effective CRT pacing results of the holter for efficacy analysis of CRT study (OLÉ CRT study). Heart Rhythm. Published online January 17, 2017, DOI:
  6. Birnie D, Lemke B, Aonuma K, et al. Clinical outcomes with synchronized left ventricular pacing: Analysis of the adaptive CRT trial. Heart Rhythm. September 2013;10(9):1368-1374.
  7. Tarab AD, Dougher CE, Rogers TB, et al. Budget impact of selecting cardiac resynchronization therapy (CRT) devices with adaptive (“aCRT”) programming algorithms under the United States Medicare payment setting. Value Health. November 2012;15(7):A349.
  8. Krum H, Lemke B, Lee KL, et al. A novel algorithm for individualized cardiac resynchronization therapy: Rationale and design of the adaptive cardiac resynchronization therapy trial. Am Heart J 2012;163(5):747-752.
  9. Singh JP, Abraham WT, Chung ES, et al. Clinical response with adaptive CRT algorithm compared with CRT with echocardiography-optimized atrioventricular delay: A retrospective analysis of multicentre trials. Europace 2013; 15(11):1622-1628.