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Immediate post renal transplant period and hypertension: concordance between clinic and ambulatory blood pressure
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Abstracts / Journal of the American Society of Hypertension 10(4S) (2016) e19–e38 BLOOD PRESSURE MEASUREMENT/MONITORING
P-38 Augmentation index is blind to early-systolic effects of arterial wave reflections Timothy S. Phan,2,3 Francisco Londono,1,3 Julio A. Chirinos,3 John K-J. Li.2 1Ghent University, Ghent, Belgium; 2Rutgers University, Piscataway, NJ, United States; 3University of Pennsylvania, Philadelphia, PA, United States Background: Markedly increased pulse wave velocity (PWV) with aging has been reported in numerous studies. Arterial wave reflection (WR) timing based on of the Augmentation Index (AI) framework does not change appreciably, despite increased PWV. The cause for this apparent discordance has not been established. Although a distal shift of reflecting sites has been proposed, this proposition has been exclusively based on the timing of the inflection point, which is a very limited approach. We hypothesize that AI is not capable of detecting early-systolic effects of reflection, particularly when PWV is high, leading to an apparent reflection-free period in early ejection. Methods: Simultaneous aortic pressure and flow were measured in anesthetized, open-chest dogs (n¼5). Intravenous infusion of methoxamine (MTX) and nitroprusside (NTP) were used to increase and decrease WRs, respectively. A coupled left ventricle-arterial system model was used to alter reflection magnitude and timing. Effects of reflection in early-systole were assessed with a systolic pressure-flow ratio (SPFR). Results: SPFR in the case of NTP remained close to aortic characteristic impedance (Zc) [horizontal dashed line] up until peak flow (Fig.1A). In control and MTX, SPFR grew increasingly divergent from Zc before peak flow (Fig.1B-C). Even when an inflection point is observed on the pressure waveform (Fig.1D, inset), SPFR diverges from Zc before the inflection, indicative of early-systole WRs. Modeling studies confirmed the dog experiments in a noise-free environment; only when wave reflections are substantially delayed and/or minimal does SPFR equal Zc in earlysystole. Divergence from this relation is due to WRs. Conclusion: WRs can alter pressure-flow relations in early-systole, prior to time of peak flow and the inflection point on the pressure waveform. Since AI is blind to early-systolic WRs, it should not be used to assess WR timing, especially when PWV is high. This is a particularly important limitation of AI to recognize when studying older subjects as well as those with hypertension in which PWV is elevated. When an appropriate method is used to gauge WR magnitude and timing in earlysystole, elevated PWV is indeed associated with earlier effects of reflections. Keywords: Wave Reflections; Augmentation Index; Hemodynamics; Pulse Wave Velocity
P-39 Immediate post renal transplant period and hypertension: concordance between clinic and ambulatory blood pressure Jose C. Prado,1 Antia Lopez,1 Gema Ruiz-Hurtado,1 Mario Fernandez,2 Jose M. Aguado,2 Amado Andres,1 Manuel Praga,1 Luis M. Ruilope,1 Julian Segura.1 do. Instituto de Investigacion Biomedica i+12. Proyecto Integrado sobre Trasplante de Organo Soli 1Hypertension Unit, Hospital 12 de Octubre, Madrid, Spain; 2Unit of Infectious Diseases, Hospital 12 de Octubre, Madrid, Spain High blood pressure (BP) strongly contributes in cardiovascular morbidity, mortality and graft survival. Ambulatory monitoring of blood pressure (ABPM) substantially improves knowledge on real BP. There is little information on the correlation between clinic and ambulatory BP in renal transplant patients in the immediate post-transplant period and its subsequent influence on cardiovascular prognosis. Our aim was to describe the degree of control of hypertension according to different clinical cut-off points and their correlation with ambulatory BP in these renal transplant patients. 61 patients who had received a kidney transplant in less than 30 days are included in this analysis. Clinic BP measurement and 24-h ABPM was performed by a Mobil-O-Graph device. Standard control was defined as systolic (S)/diastolic (D) BP <140/90 mmHg and strict control as SBP/DBP <130/80 mmHg. According to the standard control criteria, 49.2% of patients had controlled SBP and DBP, 14.8% had controlled only SBP, 19.7% had controlled only DBP, and 16.4% showed no control. According to strict criteria, control rates were 24.6%, 13.1%, 13.1% respectively, and 49.2% were not controlled. According to ABPM, the percentage of patients controlled in the daytime period (SBP <135 and DBP<85 mmHg) was 32.8%. The night-time control (SBP <120 and DBP <70 mmHg) was observed in 6.7%. Control within 24 hours (SBP <130 and DBP <80 mmHg) was observed in 24.6%. Comparing the strict clinical control with daytime ABPM period, we observed a concordance of 72.2% between the two techniques, with 21.3% of patients with isolated office hypertension and 6.6% of masked hypertension. When the standard clinical control was compared with daytime ABPM period, the concordance increased to 75.4%, with only 4.9% of isolated office hypertension but with an increased percentage of masked hypertension (19.7%). The agreement between both techniques peaked at 77.1% when comparing the strict clinical control with 24-hour ABPM, with 13.1% of isolated office hypertension and masked hypertension 9.8%. In conclusion, both clinic and ambulatory BP show a high percentage of patients with uncontrolled kidney transplant. The clinical cut-off point of 130/80 mmHg properly identify a higher percentage of patients. Uncontrolled hypertension at night-time is very prevalent. The ABPM provides additional information of great importance in the immediate post renal transplant period. Longitudinal studies with ABPM are required to assess their impact on cardiovascular prognosis in these patients. Keywords: Renal transplant; Ambulatory blood pressure monitoring; Hypertension
ANTIHYPERTENSIVE DRUGS AND PHARMACOLOGY
P-40
Figure 1.
Hydrochlorothiazide versus chlorthalidone comparison as initial monotherapy for the management of hypertension Palak Prasad,3 Sarah L. Anderson,3,1 Raymond O. Estacio,1,2 Joel C. Marrs.3,.1 1Denver Health Hospital and Authority, Denver, CO, United States; 2University of Colorado School of Medicine, Aurora, CO, United States; 3University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States
Abstracts / Journal of the American Society of Hypertension 10(4S) (2016) e19–e38 BLOOD PRESSURE MEASUREMENT/MONITORING
P-38 Augmentation index is blind to early-systolic effects of arterial wave reflections Timothy S. Phan,2,3 Francisco Londono,1,3 Julio A. Chirinos,3 John K-J. Li.2 1Ghent University, Ghent, Belgium; 2Rutgers University, Piscataway, NJ, United States; 3University of Pennsylvania, Philadelphia, PA, United States Background: Markedly increased pulse wave velocity (PWV) with aging has been reported in numerous studies. Arterial wave reflection (WR) timing based on of the Augmentation Index (AI) framework does not change appreciably, despite increased PWV. The cause for this apparent discordance has not been established. Although a distal shift of reflecting sites has been proposed, this proposition has been exclusively based on the timing of the inflection point, which is a very limited approach. We hypothesize that AI is not capable of detecting early-systolic effects of reflection, particularly when PWV is high, leading to an apparent reflection-free period in early ejection. Methods: Simultaneous aortic pressure and flow were measured in anesthetized, open-chest dogs (n¼5). Intravenous infusion of methoxamine (MTX) and nitroprusside (NTP) were used to increase and decrease WRs, respectively. A coupled left ventricle-arterial system model was used to alter reflection magnitude and timing. Effects of reflection in early-systole were assessed with a systolic pressure-flow ratio (SPFR). Results: SPFR in the case of NTP remained close to aortic characteristic impedance (Zc) [horizontal dashed line] up until peak flow (Fig.1A). In control and MTX, SPFR grew increasingly divergent from Zc before peak flow (Fig.1B-C). Even when an inflection point is observed on the pressure waveform (Fig.1D, inset), SPFR diverges from Zc before the inflection, indicative of early-systole WRs. Modeling studies confirmed the dog experiments in a noise-free environment; only when wave reflections are substantially delayed and/or minimal does SPFR equal Zc in earlysystole. Divergence from this relation is due to WRs. Conclusion: WRs can alter pressure-flow relations in early-systole, prior to time of peak flow and the inflection point on the pressure waveform. Since AI is blind to early-systolic WRs, it should not be used to assess WR timing, especially when PWV is high. This is a particularly important limitation of AI to recognize when studying older subjects as well as those with hypertension in which PWV is elevated. When an appropriate method is used to gauge WR magnitude and timing in earlysystole, elevated PWV is indeed associated with earlier effects of reflections. Keywords: Wave Reflections; Augmentation Index; Hemodynamics; Pulse Wave Velocity
P-39 Immediate post renal transplant period and hypertension: concordance between clinic and ambulatory blood pressure Jose C. Prado,1 Antia Lopez,1 Gema Ruiz-Hurtado,1 Mario Fernandez,2 Jose M. Aguado,2 Amado Andres,1 Manuel Praga,1 Luis M. Ruilope,1 Julian Segura.1 do. Instituto de Investigacion Biomedica i+12. Proyecto Integrado sobre Trasplante de Organo Soli 1Hypertension Unit, Hospital 12 de Octubre, Madrid, Spain; 2Unit of Infectious Diseases, Hospital 12 de Octubre, Madrid, Spain High blood pressure (BP) strongly contributes in cardiovascular morbidity, mortality and graft survival. Ambulatory monitoring of blood pressure (ABPM) substantially improves knowledge on real BP. There is little information on the correlation between clinic and ambulatory BP in renal transplant patients in the immediate post-transplant period and its subsequent influence on cardiovascular prognosis. Our aim was to describe the degree of control of hypertension according to different clinical cut-off points and their correlation with ambulatory BP in these renal transplant patients. 61 patients who had received a kidney transplant in less than 30 days are included in this analysis. Clinic BP measurement and 24-h ABPM was performed by a Mobil-O-Graph device. Standard control was defined as systolic (S)/diastolic (D) BP <140/90 mmHg and strict control as SBP/DBP <130/80 mmHg. According to the standard control criteria, 49.2% of patients had controlled SBP and DBP, 14.8% had controlled only SBP, 19.7% had controlled only DBP, and 16.4% showed no control. According to strict criteria, control rates were 24.6%, 13.1%, 13.1% respectively, and 49.2% were not controlled. According to ABPM, the percentage of patients controlled in the daytime period (SBP <135 and DBP<85 mmHg) was 32.8%. The night-time control (SBP <120 and DBP <70 mmHg) was observed in 6.7%. Control within 24 hours (SBP <130 and DBP <80 mmHg) was observed in 24.6%. Comparing the strict clinical control with daytime ABPM period, we observed a concordance of 72.2% between the two techniques, with 21.3% of patients with isolated office hypertension and 6.6% of masked hypertension. When the standard clinical control was compared with daytime ABPM period, the concordance increased to 75.4%, with only 4.9% of isolated office hypertension but with an increased percentage of masked hypertension (19.7%). The agreement between both techniques peaked at 77.1% when comparing the strict clinical control with 24-hour ABPM, with 13.1% of isolated office hypertension and masked hypertension 9.8%. In conclusion, both clinic and ambulatory BP show a high percentage of patients with uncontrolled kidney transplant. The clinical cut-off point of 130/80 mmHg properly identify a higher percentage of patients. Uncontrolled hypertension at night-time is very prevalent. The ABPM provides additional information of great importance in the immediate post renal transplant period. Longitudinal studies with ABPM are required to assess their impact on cardiovascular prognosis in these patients. Keywords: Renal transplant; Ambulatory blood pressure monitoring; Hypertension
ANTIHYPERTENSIVE DRUGS AND PHARMACOLOGY
P-40
Figure 1.
Hydrochlorothiazide versus chlorthalidone comparison as initial monotherapy for the management of hypertension Palak Prasad,3 Sarah L. Anderson,3,1 Raymond O. Estacio,1,2 Joel C. Marrs.3,.1 1Denver Health Hospital and Authority, Denver, CO, United States; 2University of Colorado School of Medicine, Aurora, CO, United States; 3University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States