The Haemodynamic Instability Score (HIS) for assessment of cardiovascular reactivity in hypertensive and normotensive patients

The association between the type of anesthesia and hemodynamic instability during pheochromocytoma surgery: a retrospective cohort study

BACKGROUND

Pheochromocytoma often carries a risk for perioperative hemodynamic instability (HDI). The aim of this study is to evaluate the risk factors of intraoperative HDI during minimally invasive posterior retroperitoneal adrenalectomy (PRA) for pheochromocytoma.

MATERIALS AND METHODS

This retrospective study analyzed the prospectively collected data of 172 patients who underwent laparoscopic PRA or robotic PRA for pheochromocytoma between January 2014 and December 2020 at a single tertiary center. The patients were divided into two groups according to the intraoperative hypertensive event of systolic blood pressure (> 160 mmHg). The clinical manifestations and perioperative hemodynamic conditions were analysed.

RESULTS

In the multivariate logistic regression analysis, the tumor size (> 3.4 cm) [OR 3.14, 95% confidence intervals (CI) (1.48-6.64), p = 0.003], type of preoperative alpha-blocker (selective type) [OR 3.9, 95% CI (1.52-10.02), p = 0.005], preoperative use of beta-blockers [OR 3.94, 95% CI (1.07-14.49), p = 0.039] and type of anesthesia [total intravenous anesthesia (TIVA) vs. balanced anesthesia (BA)] [OR 2.57, 95% CI (1.23-5.38), p = 0.012] were determined as independent risk factors of intraoperative hypertensive events during minimally invasive adrenalectomy.

CONCLUSIONS

The type of anesthesia was independently associated with intraoperative HDI along with larger tumor size, type of preoperative alpha-blocker and the use of preoperative beta-blockers. TIVA increased the risk of intraoperative hypertensive events compared with BA. Thus, the consideration of the type of anesthesia prior to adrenal surgery for pheochromocytoma along with the use of preoperative non-selective alpha-blockers may be beneficial in minimizing the risk of intraoperative HDI.

An Emerging Role for Understanding Orthostatic Hyp'er'tension in the Cardiorenal Syndrome

Orthostatic hypertension (OHT) is a clinically important problem increasingly recognized in persons with borderline hypertension, diabetes mellitus, and autonomic neuropathies, and in the elderly. Moreover, the association of OHT with progression of target end-organ damage, especially coronary heart disease and chronic kidney disease (CKD), and the attendant increased cardiovascular disease (CVD) and CKD risk, is gaining attention but is still underappreciated. There are various mechanisms that contribute to the development of OHT: excessive vascular adrenergic sensitivity, baroreceptor reflex abnormalities, and inappropriate activation of the renin-angiotensin-aldosterone system, which are also mechanisms that lead to cardiorenal metabolic disease (CRS). While the evidence is compelling for the clinical importance of OHT, more investigation is needed to evaluate the effects of OHT on CKD and CVD. The notion that the development of OHT is a risk factor for the development of CRS raises the need for further clinical and investigational attention to this clinical dilemma.

Cerebro- and cardiovascular reactivity and neuropsychological performance in hypertensive patients

BACKGROUND

Hypertensive (HT) patients are at higher risk of cognitive decline than normotensive individuals, because high blood pressure is a risk factor for mild cognitive deterioration. In this study cardio- and cerebrovascular reactivity along with cognitive performance was assessed on newly diagnosed HT patients.

METHODS

Diagnosis of hypertension was based on international recommendations. None of the patients had diabetes, and all of them had normal cerebral CT scan. Eighty-one patients (43.5±10.2 years, male/female ratio: 42/39) were compared with 94 healthy controls (44±9.4 years, male/female ratio: 50/44). In both groups continuous, non-invasive and simultaneous monitoring of cerebral and cardiac hemodynamical parameters were recorded during head-up tilt table testing (HUTT). Reaction time, attention and memory skills, anxiety and depression rate were determined by neuropsychological tests.

RESULTS

During HUTT significant differences were found in certain cardiovascular parameters (blood pressure, total peripheral resistance index, stroke index), but no differences were detected in cerebral blood flow velocity. While there was no significant difference in reaction time between the two groups, tests estimating short-term memory (Digit Span Test) differed significantly. Moreover, sum of standardized test scores was significantly lower, while anxiety level was significantly increased in HT patients compared to controls.

CONCLUSION

Decrease in neuropsychological performance along with alterations of cardiovascular parameters is an early manifestation of hypertension. Aim for an early intervention and accurate treatment is crucial for preventing further impairments.

Search for disease-specific cardiovascular reactivity patterns: developing the methodology

Aberrations of CVR (cardiovascular reactivity), an expression of autonomic function, lack specificity for a particular disorder. Recently, a CVR pattern particular to chronic fatigue syndrome has been observed. In the present study, we aimed to develop methodologies for assessing disease-specific CVR patterns. As a prototype, a population of 50 consecutive patients with FMF (familial Mediterranean fever) was studied and compared with control populations. A 10 min supine/30 min head-up tilt test with recording of the heart rate and blood pressure or the pulse transit time was performed. Five studies were conducted applying different methods. In each study, statistical analysis identified independent predictors of CVR in FMF. Based on regression coefficients of these predictors, a linear DS (discriminant score) was computed for every subject. Each study established an equation to assess CVR, calculate DS for FMF and determine the sensitivity and specificity of the DS cut-off. In each of the five studies, abnormal CVR was observed in FMF patients. The best accuracy (88% sensitivity and 90.1% specificity for FMF) was obtained by a method based on beat-to-beat heart rate and pulse transit time recordings. Data was processed by fractal and recurrence quantitative analysis with recordings in FMF patients compared with a mixed control population. Identification of disease-specific CVR patterns was possible with the methodologies described in the present study. In FMF, disease-specific CVR may be explained by the interplay between neuroendocrine loops specific to FMF with cardiovascular homoeostatic mechanisms. Recognition of disease-specific CVR patterns may advance the understanding of homoeostatic mechanisms and have implications in clinical practice.

Cardiovascular reactivity score for the assessment of dysautonomia in familial Mediterranean fever

OBJECTIVE

The aim of this study was to assess the presence of dysautonomia, as manifested in abnormal cardiovascular reactivity, in patients with familial Mediterranean fever (FMF).

METHODS

Fifty-five consecutive patients with FMF and 23 age- and sex-matched healthy controls were evaluated. Cardiovascular reactivity was studied: (1) using recordings of blood pressure (BP) and heart rate (HR) during 10 min of recumbence and 30 min of head-up tilt test to identify clinical endpoints and (2) during tilt-test, identifying parameters acting as independent predictors of FMF reactivity and enabling computation of a cardiovascular reactivity score (CVRS).

RESULTS

Clinically, vasovagal reaction, postural tachycardia syndrome, and/or orthostatic hypotension were observed in ten patients (18.1%). Utilizing a derived equation, the group average CVRS in FMF was 5.83+/-1.78 (healthy group -7.60+/-5.41) ( P=<0.0001). A CVRS of >3.25 was associated with FMF, with 98% sensitivity and 100% specificity.

CONCLUSION

A very high percentage of FMF patients exhibit abnormal cardiovascular reactivity which is clinically occult but can be detected on autonomic challenge and application of the CVRS.

Assessment of cardiovascular reactivity by fractal and recurrence quantification analysis of heart rate and pulse transit time

Methods used for the assessment of cardiovascular reactivity are flawed by nonlinear dynamics of the cardiovascular responses to stimuli. In an attempt to address this issue, we utilized a short postural challenge, recorded beat-to-beat heart rate (HR) and pulse transit time (PTT), assessed the data by fractal and recurrence quantification analysis, and processed the obtained variables by multivariate statistics. A 10-min supine phase of the head-up tilt test was followed by recording 600 cardiac cycles on tilt, that is, 5-10 min. Three groups of patients were studied, each including 20 subjects matched for age and gender--healthy subjects, patients with essential hypertension (HT), and patients with chronic fatigue syndrome (CFS). The latter group was studied on account of the well-known dysautonomia of CFS patients, which served as contrast against the cardiovascular reactivity of the healthy population. A total of 52 variables of the HR and PTT were determined in each subject. The multivariate model identified the best predictors for the assessment of reactivity of healthy subjects vs CFS. Based on these predictors, the "Fractal & Recurrence Analysis-based Score" (FRAS) was calculated: FRAS=76.2+0.04*HR-supine-DET -12.9*HR-tilt-R/L -0.31*HR-tilt-s.d. -19.27*PTT-tilt-R/L -9.42*PTT-tilt-WAVE. The median values and IQR of FRAS in the groups were: healthy=-1.85 (IQR 1.89), hypertensives=+0.52 (IQR 5.78), and CFS=-24.2 (5.34) (HT vs healthy subjects: P=0.0036; HT vs CFS: P<0.0001). Since the FRAS differed significantly between the three groups, it appears likely that the FRAS may recognize phenotypes of cardiovascular reactivity.

Hemodynamics instability score in chronic fatigue syndrome and in non-chronic fatigue syndrome

OBJECTIVE

In studying patients with chronic fatigue syndrome (CFS) we developed a method that confers numerical expression to the degree of blood pressure and heart rate lability, ie, the 'hemodynamic instability score' (HIS). The HIS in CFS patients differed significantly from healthy subjects. The present investigation compares the HIS in CFS, non-CFS chronic fatigue and patients with recurrent syncope.

METHODS

Patients with CFS (n = 21), non-CFS chronic fatigue (n = 24), syncope of unknown cause (n = 44), and their age and sex-matched healthy controls (n = 21) were evaluated with a standardized head-up tilt test (HUTT). Abnormal reactions (endpoints) on HUTT were classified 'clinical outcomes' (cardioinhibitory or vasodepressor reaction, orthostatic hypotension, postural tachycardia syndrome) and 'HIS endpoint', i.e. HIS >-0.98.

RESULTS

The highest incidence of endpoints was noted in patients with CFS (79%), followed by patients with syncope of unknown cause (46%), non-CFS chronic fatigue (35%), and healthy subjects (14%). Presyncope or syncope during tilt occurred in 38% of CFS patients, 21% of patients with non-CFS chronic fatigue, and 43% of patients with recurrent syncope. The average HIS values were: CFS = +2.02 (SD 4.07), non-CFS chronic fatigue = -2.89 (SD 3.64), syncope = -3.2 (SD 3.0), healthy = -2.48 (4.07). The odds ratios for CFS patients to have HIS >-0.98 was 8.8 compared with non-CFS chronic fatigue patients, 14.6 compared with recurrent syncope patients, and 34.8 compared with healthy subjects.

CONCLUSION

The cardiovascular reactivity in patients with CFS has certain features in common with the reactivity in patients with recurrent syncope or non-CFS chronic fatigue, such as the frequent occurrence of vasodepressor reaction, cardioinhibitory reaction, and postural tachycardia syndrome. Apart from to these shared responses, the large majority of CFS patients exhibit a particular abnormality which is characterized by HIS values >-0.98. Thus, HIS >-0.98 lends objective criteria to the assessment of CFS.

Hemodynamic instability in chronic fatigue syndrome: indices and diagnostic significance

OBJECTIVES

To evaluate the cardiovascular response to postural challenge in patients with chronic fatigue syndrome (CFS) and to determine whether the degree of instability of the cardiovascular response may aid in diagnosing CFS.

METHODS

Patients with CFS (n = 25) and their age- and gender-matched healthy controls (n = 37), patients with fibromyalgia (n = 30), generalized anxiety disorder (n = 15), and essential hypertension (n = 20) were evaluated with the aid of a standardized tilt test. The blood pressure (BP) and heart rate (HR) were recorded during 10 minutes of recumbence and 30 minutes of head-up tilt. We designated BP changes as the differences between successive BP values and the last recumbent BP. The average and standard deviation (SD) were calculated. Time curves of BP differences were loaded into a computerized image analyzer, and their outline ratios and fractal dimensions were measured. HR changes were determined similarly. The average and SD of the parameters were calculated, and intergroup comparisons were performed.

RESULTS

On multivariate analysis, the independent predictors of CFS patients versus healthy controls were the fractal dimension of absolute values of the systolic BP changes (SYST-FD.abs), the standard deviation of the current values of the systolic BP changes (SYST-SD.cur), and the standard deviation of the current values of the heart rate changes (HR-SD.cur). The following equation was deduced to calculate the hemodynamic instability score (HIS) in the individual patient: HIS = 64.3303 + (SYST-FD.abs x -68.0135) + (SYST-SD.cur x 111.3726) + (HR-SD.cur x 60.4164). The best cutoff differentiating CFS from the healthy controls was -0.98. HIS values >-0.98 were associated with CFS (sensitivity 97%, specificity 97%). The HIS differed significantly between CFS and other groups (P <.0001) except for generalized anxiety disorder. Group averages (SD) of HIS were CFS = +3.72 (5.02), healthy = -4.62 (2.26), fibromyalgia = -3.27 (2.63), hypertension = -5.53 (2.24), and generalized anxiety disorder = +1.08 (5.2).

CONCLUSION

The HIS adds objective criteria confirming the diagnosis of CFS.