Estella Pulse Generators - BIOTRONIK USA - News

Estella Pulse Generators Technical Manual 216. Clinical Study6.1 Dromos DRPrimary Objectives: To evaluate the safety and effectiveness of theDromos DR pulse generator and the utility of the DDDR pacing modein patients with chronotropic incompetence (CI) in a crossover, doubleblindtrial. CI was defined as the inability to achieve a heart rate of a)60% of their age predicted maximum (220-age), or b) 100 bpm.Patients, Methods and Results: A total of 273 patients were implantedwith the Dromos DR pulse generator between July 21, 1995 and July 31,1996, at 34 investigational centers (32 in the US, 1 France, and 1Mexico). Mean patient age was 71 years with a range of 31 to 95, and145 of 273 (53%) were male. Pre-implantation clinical symptomologywas: bradycardia in 44% of the patients, dizziness in 31%, syncope in25%, ECG indications were: Sick Sinus Syndrome in 46%, heart blockin 40%, and atrial fibrillation/atrial flutter in 13% of the patients. Themean implant duration was 5.2 months (range = 0 to 16 months) with atotal implant experience of 1418 months. At the one-month follow‐up,212 patients (91%) were programmed to a rate-adaptive mode accordingto the sensor parameter optimization procedure. Of the 63 patientscompleting a DDD exercise test (CAEP protocol) at one‐month, 25were found to be CI, and 21 completed the paired exercise testing atsix‐weeks. Patients performed the exercise tests, including metabolicmeasurements, in both the DDD and DDDR modes in randomized order.Table 3: Dromos DR Metabolic Exercise Testing at 6 WeeksEndpointsMaximum VO 2(mL/kg/minute)DDDRModeDDD Mode20.4 ± 8.0 17.8 ± 6.2VO 2@ AT (mL/kg/minute) 14.6 ± 3.6 13.1 ± 4.0Total exercise time(minutes)Exercise time to AT(minutes)9.2 ± 3.0 8.2 ± 3.36.3 ± 2.4 5.7 ± 2.8Heart rate @AT (bpm) 113 ± 16 84 ± 16.5Difference (CI)2.67* ± 2.77[1.5, 3.8]1.5* ± 2.71[0.33, 2.6]0.92* ± 1.08[0.45,1.4]0.69* ± 1.43[0.04, 1.3]29* ± 18[21,37]All chronotropically incompetent patients tested, n =21, Mean ±SD and [95% confidenceinterval] 95% confidence interval = mean difference ± 1.96 SEM* Difference statistically significant, p