ABSTRACT
BACKGROUND: Considerable proportion of patients does not respond to the cardiac resynchronization therapy (CRT). This study investigated clinical relevance of left ventricular electrode local electrogram delay from the beginning of QRS (QLV). We hypothesized that longer QLV indicating more optimal lead placement in the late activated regions is associated with the higher probability of positive CRT response. METHODS: We conducted a retrospective, single-centre analysis of 161 consecutive patients with heart failure and LBBB or nonspecific intraventricular conduction delay (IVCD) treated with CRT. We routinely intend to implant the LV lead in a region with long QLV. Clinical response to CRT, left ventricular (LV) reverse remodelling (i.e. decrease in LV end-systolic diameter - LVESD ≥10%) and reduction in plasma level of NT-proBNP >30% at 12-month post-implant were the study endpoints. We analyzed association between pre-implant variables and the study endpoints. RESULTS: Clinical CRT response rate reached 58%, 84% and 92% in the lowest (≤105 ms), middle (106-130 ms) and the highest (>130 ms) QLV tertile (p < 0.0001), respectively. Longer QRS duration (p = 0.002), smaller LVESD and a non-ischemic cardiomyopathy (both p = 0.02) were also univariately associated with positive clinical CRT response. In a multivariate analysis, QLV remained the strongest predictor of clinical CRT response (p < 0.00001), followed by LVESD (p = 0.01) and etiology of LV dysfunction (p = 0.04). Comparable predictive power of QLV for LV reverse remodelling and NT-proBNP response rates was observed. CONCLUSION: LV lead position assessed by duration of the QLV interval was found the strongest independent predictor of beneficial clinical response to CRT.
Subject(s)
Cardiac Resynchronization Therapy Devices , Cardiac Resynchronization Therapy , Electrophysiologic Techniques, Cardiac , Heart Block/therapy , Heart Failure/therapy , Ventricular Function, Left , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Bundle-Branch Block/physiopathology , Bundle-Branch Block/therapy , Cardiac Resynchronization Therapy/adverse effects , Chi-Square Distribution , Czech Republic , Equipment Design , Female , Heart Block/blood , Heart Block/physiopathology , Heart Failure/blood , Heart Failure/physiopathology , Humans , Linear Models , Male , Middle Aged , Multivariate Analysis , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Predictive Value of Tests , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Ventricular RemodelingABSTRACT
Standard formulas for predicting postoperative forced expiratory volume in 1 second (po-FEV1) do not consider bronchi obstructed by tumor or chronic obstructive pulmonary disease, e.g., Formula 1 [ppo-FEV1 = (pre-opFEV,) x (# segments remaining)/(# of total segments)] whereas Formula 2 [ppo-FEV1 = (pre-opFEV,) x (# segments remaining)/(# of total unobstructed segments)] does. A retrospective chart review was conducted to determine accuracy of predicting po-FEV1, at a comprehensive cancer center. Predicted po-FEV, was calculated using different formulas and analyzed using regression analysis and Pearson correlation. We found good correlation between po-FEV1 and predicted po-FEV1 using Formulas 1 and 2. In patients with tumor airway obstruction or chronic obstructive pulmonary disease, predictive accuracy decreased for both formulas. Prediction of FEV1 in patients undergoing pulmonary resection was generally accurate, but major errors were observed in some cases; therefore, better predictive formulas are needed in patients with airway obstruction by tumor or chronic obstructive pulmonary disease.