Katarzyna Styczkiewicz

Pulsatile but Not Steady Component of Blood Pressure Predicts Cardiovascular Events in Coronary Patients

Although the differences between central and peripheral blood pressure (BP) values have been known for decades, the consequences of decision making based on peripheral rather than central BP have only recently been recognized. There are only a few studies assessing the relationship between intraaortic BP and cardiovascular risk. In addition, the relationship between central BP and the risk of cardiovascular events in a large group of coronary patients has not yet been evaluated. Therefore, the aim of the study was to determine the prognostic significance of central BP-derived indices in patients undergoing coronary angiography. Invasive central BPs were taken at baseline, and study end points were ascertained during over a 4.5-year follow-up in 1109 consecutive patients. The primary end point (cardiovascular death or myocardial infarction or stroke or cardiac arrest or heart transplantation or myocardial revascularization) occurred in 246 (22.2%) patients. Central pulsatility was the most powerful predictor of the primary end point (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.14 to 1.48). Central pulse pressure was also independently related to the primary end point (HR 1.25, 95% CI 1.09 to 1.43). Central mean BP as well as peripheral BP parameters were not independently related to the primary end point risk. Central pulsatility was also related to risk of cardiovascular death or myocardial infarction or stroke. The pulsatile component of BP is the most important factor related to the cardiovascular risk in coronary patients. It is more closely associated with cardiovascular risk than steady component of BP.

A new method for assessing 24-h blood pressure variability after excluding the contribution of nocturnal blood pressure fall.

Objectives To assess quantitatively the relationship between nocturnal blood pressure (BP) fall and 24-h BP variability; to propose a new method for computing 24-h BP variability, devoid of the contribution from nocturnal BP fall; and to verify the clinical value of this method. Methods and results We analysed 3863 ambulatory BP recordings, and computed: (1) the standard deviation (SD) of 24-h BP directly from all individual readings and as a weighted mean of daytime and night-time SD (wSD); and (2) the size of nocturnal BP fall. Left ventricular mass index (LVMI) was assessed by echocardiography in 339 of the patients. The 24-h SD of BP was significantly greater than the 24-h wSD. Nocturnal BP fall was strongly and directly related to 24-h SD, the relationship with 24-h wSD being much weaker and inverse. The difference between SD and wSD was almost exclusively determined by the size of nocturnal BP fall. wSD of systolic BP was significantly related to LVMI, while 24-h SD was not. Conclusion Conventional 24-h SD of BP is markedly influenced by nocturnal BP fall. The weighted 24-h SD of BP removes the mathematical interference from night-time BP fall and correlates better with end-organ damage, therefore it may be considered as a simple index of 24-h BP variability superior to conventional 24-h SD.

Effects of selective and nonselective beta-blockade on 24-h ambulatory blood pressure under hypobaric hypoxia at altitude

Background Little is known about the effects of cardiovascular drugs at high altitude. Objective To assess 24-h blood pressure (BP) and heart rate (HR) during short-term altitude exposure in healthy normotensive persons treated with carvedilol or nebivolol. Methods Participants were randomized in double-blind to placebo, nebivolol 5 mg once daily or carvedilol 25 mg b.i.d. Tests were performed at sea level (baseline and after 2 weeks treatment) and on second to third day at altitude (Monte Rosa, 4559 m), still on treatment. Data collection included conventional BP, 24-h ambulatory BP monitoring (ABPM), oxygen saturation (SpO2), Lake Louise Score and adverse symptoms score. Results Twenty-four participants had complete data (36.4 ± 12.8 years, 14 men). Both beta-blockers reduced 24-h BP at sea level. At altitude 24-h BP increased in all groups, mainly due to increased night-time BP. Twenty-four-hour SBP at altitude was lower with carvedilol (116.4 ± 2.1 mmHg) than with placebo (125.8 ± 2.2 mmHg; P < 0.05) and intermediate with nebivolol (120.7 ± 2.1 mmHg; NS vs. others). Rate of nondipping increased at altitude and was lower with nebivolol than with placebo (33 vs. 71%; P = 0.065). Side effects score was higher with carvedilol than with placebo (P = 0.04), and intermediate with nebivolol. SpO2 at altitude was higher with placebo (86.1 ± 1.2%) than with nebivolol (81.7 ± 1.1%; P = 0.07) or carvedilol (81.1 ± 1.1%; P = 0.04). Conclusions Both carvedilol and nebivolol partly counteract the increase in BP at altitude in healthy normotensive individuals but are associated with a lower SpO2. Carvedilol seems more potent in this regard, whereas nebivolol more effectively prevents the shift to a nondipping BP profile and is better tolerated.

Effects of beta-blockade on exercise performance at high altitude: a randomized, placebo-controlled trial comparing the efficacy of nebivolol versus carvedilol in healthy subjects.

AIMS Exposure to high altitude (HA) hypoxia decreases exercise performance in healthy subjects. Although β-blockers are known to affect exercise capacity in normoxia, no data are available comparing selective and nonselective β-adrenergic blockade on exercise performance in healthy subjects acutely exposed to HA hypoxia. We compared the impact of nebivolol and carvedilol on exercise capacity in healthy subjects acutely exposed to HA hypobaric hypoxia. METHODS In this double-blind, placebo-controlled trial, 27 healthy untrained sea-level (SL) residents (15 males, age 38.3 ± 12.8 years) were randomized to placebo (n = 9), carvedilol 25 mg b.i.d. (n = 9), or nebivolol 5 mg o.d. (n = 9). Primary endpoints were measures of exercise performance evaluated by cardiopulmonary exercise testing at sea level without treatment, and after at least 3 weeks of treatment, both at SL and shortly after arrival at HA (4559 m). RESULTS HA hypoxia significantly decreased resting and peak oxygen saturation, peak workload, VO(2) , and heart rate (HR) (P < 0.01). Changes from SL (no treatment) differed among treatments: (1) peak VO(2) was better preserved with nebivolol (-22.5%) than with carvedilol (-37.6%) (P < 0.01); (2) peak HR decreased with carvedilol (-43.9 ± 11.9 beats/min) more than with nebivolol (-24.8 ± 13.6 beats/min) (P < 0.05); (3) peak minute ventilation (VE) decreased with carvedilol (-9.3%) and increased with nebivolol (+15.2%) (P= 0.053). Only peak VE changes independently predicted changes in peak VO(2) at multivariate analysis (R= 0.62, P < 0.01). CONCLUSIONS Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to HA hypoxia in healthy subjects.

How to improve the assessment of 24-h blood pressure variability

An increased 24-h blood pressure variability, expressed as SD of 24-h average ambulatory blood pressure values, is associated with target organ damage and cardiovascular risk in hypertension, while a physiological nocturnal blood pressure fall has been associated with reduced cardiovascular risk. Nocturnal blood pressure fall, however, may contribute markedly to the overall blood pressure variability. The aim of our study was to quantitatively assess the contribution of nocturnal blood pressure fall to 24-h blood pressure variability, and to propose a new method for computing 24-h blood pressure variability correcting for nocturnal blood pressure fall. From a large database of ambulatory blood pressure recordings obtained in two hypertension centres (Milan, Italy and Krakow, Poland), we selected 1995 recordings of a sufficiently high quality (≥70% valid readings, ≥1 measure/h). We calculated (1) blood pressure variability, as SD of 24-h mean blood pressure, both directly from all 24-h individual readings and as a weighted mean of separately computed daytime and night-time blood pressure SD; and (2) the size of nocturnal blood pressure fall. The weighted mean SD of 24-h blood pressure was significantly lower than the corresponding direct 24-h SD of blood pressure. The size of the difference between direct SD and weighted mean SD was strongly correlated with the absolute size of nocturnal blood pressure fall (SD: r=0.89 and 0.86 for systolic and diastolic blood pressures, respectively, P<0.001 for all). The 24-h SD of blood pressure is markedly influenced by the size of nocturnal blood pressure fall, while the weighted mean SD is not. The inclusion of nocturnal blood pressure fall in the calculation of 24-h blood pressure variability may thus lead to the overestimating of this phenomenon. Given that blood pressure variability and fall at night may have opposite prognostic significance, it may be advisable to calculate 24-h SD as the weighted mean of daytime and night-time values, which excludes the interference of night-time blood pressure fall on overall blood pressure variability and allows a more precise assessment of the clinical value of 24-h blood pressure variability. The actual clinical relevance of this new parameter has to be assessed by longitudinal outcome studies.

Effects of device-guided slow breathing training on exercise capacity, cardiac function, and respiratory patterns during sleep in male and female patients with chronic heart failure

INTRODUCTION Slow breathing training (SBT) has been proposed as a new nonpharmacologic treatment in patients with chronic heart failure (CHF). OBJECTIVES The aim of this study was to assess the effects of SBT on exercise capacity, hemodynamic parameters, and sleep respiratory patterns in a relatively large sample of CHF patients. PATIENTS AND METHODS A crossover open study was conducted. Patients completed, in a random order, 10- to 12‑week SBT, with 2 15‑minute sessions of device‑guided SBT each day, reaching 6 breaths/ min, and a 10- to 12‑week follow‑up under standard care. Clinical data collection, polysomnography, echocardiography, 6‑minute walk test (6MWT), and laboratory tests were performed. RESULTS A total of 96 patients (74 men, 22 women) in New York Heart Association classes I-III, with an average age of 65 years and an ejection fraction (EF) of 31%, completed the study. Home‑based SBT was safe. After training, EF and 6MWT distance improved (EF: 31.3% ±7.3% vs 32.3% ±7.7%; P = 0.030; 6MWT: 449.9 ±122.7 m vs 468.3 ±121.9 m; P <0.001), and the apnea-hypopnea index decreased (5.6 [interquartile range (IQR), 2.1; 12.8] vs. 5.4 [IQR, 2.0; 10.8]; P = 0.043). CONCLUSIONS SBT improved physical capacity and systolic heart function; it also diminished sleep disturbances. The results support the benefits of SBT as a novel component of cardiorespiratory rehabilitation programs in patients with CHF.

Tyrosine kinase inhibitors – should we worry about cardiovascular complications?

Small-molecular tyrosine kinase inhibitors constitute an effective therapeutic option in patients with hematologic malignancies and solid tumours. On the other hand, the significance of cardiovascular adverse events associated with their use is often emphasised. The events include arterial hypertension, heart failure, coronary disease/acute coronary syndromes, and long QT syndrome. The paper discusses the underlying mechanisms behind cardiovascular events associated with the treatment that involves tyrosine kinase inhibitors, and presents preventive and therapeutic options available in clinical practice. Awareness of the potential cardiovascular complications, regular follow-up, early diagnosis and initiation of appropriate treatment, combined with close collaboration with cardiology specialists, may enhance the benefits of long-term TKI therapy.

[PP.20.08] THE INFLUENCE OF SLOW BREATHING TRAINING ON QUALITY OF LIFE IN PATIENTS WITH CHRONIC HEART FAILURE

Objective: Slow breathing training (SBT) was shown to have favorable acute effects in chronic heart failure (CHF) patients. Aim of this study was to test the influence of SBT on quality of life (QoL) in these patients. Design and method: The study was a cross-over open trial where patients, in random order, underwent a 10–12 week period of SBT with RESPeRATE device (InterCure Ltd., Lod, Israel) and a 10–12 week follow-up under usual care. Patients during SBT were asked to perform each day two separate 15-min sessions of device-guided SBT at a breathing frequency of 6 breaths per minute. In all patients QoL was assessed with Minnesota Living with Heart Failure questionnaire performed at baseline and after each study phase. QoL was assessed both globally and separately for physical, socio-economical and emotional aspects. Results: 74 patients completed the study. with the following baseline characteristics: age 62.9 ± 11.9 years, 59 M/15F, 52 with ischemic CHF, NYHA Class I:7 Class II:51, Class III:16, left ventricular ejection fraction 30.4 ± 8.1 %, hypertension: 47, history of stroke: 5, diabetes: 28. In subjects who completed SBT phase, total and physical QoL scores before and after SBT were 49.0 (41.0–56.0) vs 46.0 (37.5–52.0), p < 0.001, and 22.0 (19.0–25.0) vs. 20.0 (16.0–23.0), p = 0.006, respectively. There were no significant differences in socio-economical [21.5 (17.0–24.0) vs. 21.0 (16.0–23.0); p = 0.200] and emotional [5.0 (3.0–7.0) vs 4.0 (3.0–6.0); p = 0.718] aspects of QoL. Conclusions: Our data indicate that SBT is safe in CHF subjects, and may improve their quality of life, mostly due to an improvement in exercise capacity. These results are in line with our previous finding of increased 6 minute walk distance in this sample, and further support SBT as a novel and useful component of cardiorespiratory rehabilitation programs in CHF.

Quality of Life in Patients with Cardiac Rhythm Disturbances

In recent years, radical changes have been observed in the treatment of disturbances in cardiac rhythm. Multicenter clinical studies have allowed for better understanding of the pathogenesis of rhythm disturbances. Treatment options have been aimed at reducing mortality and improving health-related quality of life (HRQoL). Despite advances in pharmacotherapy and electrotherapy, many patients with rhythm disturbances experience various symptoms which often do not allow them to participate in everyday activities. Though the circumstances surrounding the occurrence of arrhythmia are unpredictable, the QoL of patients is influenced by the frequency and duration of attacks as well as the degree to which symptoms are exacerbated. Sudden and frequent hospitalizations due to arrhythmia as well as the side effects of antiarrhythmic drugs also constitute a severe burden for patients.

THE INFLUENCE OF CARDIAC RESYNCHRONIZATION THERAPY IN CHRONIC HEART FAILURE ON RESPIRATORY PROFILE AND AUTONOMIC MODULATION: PP.1.29

Aim: Cardiac resynchronization therapy (CRT) has been demonstrated to have a favorably impact on clinical outcome in patients with chronic heart failure (CHF). The aim of our study was to determine the effect of CRT on respiratory profile and autonomic modulation in CHF. Methods: Into our pilot analysis we included only CHF patients in NYHA class III presenting with sinus rhythm (N=8, mean age: 60.20 ± 7.85yr, mean EF 23.22 ± 6.70%). In all patients, beat-to-beat blood pressure (BP) monitoring and polysomnography were performed. Baroreflex function was assessed by the sequence technique (PI/SBP sequences). Based on polysomnography recording apnea-hypopnoea index (AHI), mean oxygen saturation, number of central, obstructive, mixed apneas and hypopnoea were calculated. Subjective sleep quality was assessed by the Pittsburg Sleep Quality Index (PSQI). All data was evaluated before CRT implantation procedure and after 3 months. Results: As compared to baseline after CRT therapy we observed a trend toward increase of BRS after the CRT therapy assessed by sequence technique (5.60 ± 0.09 vs 9.69 ± 8.22 ms/mmHg). All patients have breathing abnormalities with AHI > 5. CRT led to insignificant decrease in central apnoeas (187.66 ± 62.77 vs 74.66 ± 103.36, p = 0.1) along with a trend of increase in mixed and obstructive apnea number and hypopnoea number. No changes were noticed pertaining AHI (41.76 ± 8,6 vs 40.26 ± 21.6, NS), mean oxygen saturation (93.16 ± 1.40 vs 92.53 ± 1.58, NS) and PSQI (6.33 ± 2.08 vs 5.33 ± 1.15, NS). Conclusions: CRT therapy may lead to insignificant improvement in autonomic regulation and change in respiratory pattern shifting the balance between central and other breathing disordered events toward the latter ones. The role of this observation, its mechanism and prognostic implications deserves to be determined on a larger patients group in a prospective study.