Cardiac risk stratification in elective non-cardiac surgery: role of NT-proBNP.

AIM: The aim of the study was to investigate the utility of NT-proBNP measurement for the stratification of presurgical cardiac risk. METHODS: Cardiac risk before elective non-cardiac surgery was evaluated in 82 consecutive patients. From each patient a venous blood sample was drawn to determinate NT-proBNP levels. Patients were followed up over three months in order to detect the occurrence of cardiac adverse events. RESULTS: NT-proBNP was positively correlated (P<0.0001) with age, days of hospitalization (P=0.001) and ASA class (P=0.001). High surgical risk (P<0.0001), diabetes (P=0.004), dyslipidemia (P=0.006) and elevated levels of NT-proBNP (P<0.0001) were significantly correlated with events. Using a logistic regression analysis we found an independent association between pre-operative elevated NT-proBNP and postoperative cardiac events (OR 1.2, 95% CI 1.0-1.4, P=0.01). CONCLUSION: Measuring NT-proBNP before non cardiac surgery in clinical practice could be useful to better stratify patients' risk.

[Blood pressure variability]. / La variabilità della pressione arteriosa.

This review deals with a number of issues related to blood pressure variability. These include: historical aspects, with reference to the first pioneering observations; methodological aspects, focusing on the different methods for quantifying blood pressure variability; description of the characteristics of blood pressure variability over the 24 hours; mechanisms involved in determining the different magnitude of this phenomenon in different subjects, such as behavioral factors, central and reflex neural influences, humoral and mechanical factors; blood pressure variability as a probe to assess spontaneous baroreflex sensitivity; effects of aging and hypertension on blood pressure variability, with a discussion of the clinical relevance of this phenomenon in the prognostic evaluation of patients; effects of drugs on blood pressure variability. Finally methodological aspects related to the use of noninvasive ambulatory blood pressure monitoring in the assessment of blood pressure variability are discussed.

Clinical value of blood pressure variability.

Blood pressure (BP) is known to continuously fluctuate over time and both the amplitude and frequency of these changes have been reported to be clinically relevant. Indeed, it has been shown that the occurrence of pronounced BP changes at the time of the physician's visit may introduce errors in the diagnosis of hypertension and in the assessment of the efficacy of antihypertensive treatment. Moreover, several studies have provided evidence that the end organ damage of hypertension is not only more closely related to 24h average BP values than to casual BP readings, it is also significantly and independently related to the degree of BP variability during the day and night. Results from a recent follow-up study support the possibility that the degree of BP variability may also have prognostic relevance in hypertensive patients. Recent progress in technology has offered us non-invasive techniques for the assessment of beat-to-beat finger blood pressure variability and for the detailed quantification of all its frequency components from the fastest to the slowest ones. Their role as additional surrogate endpoints in essential hypertension needs to be addressed in future studies.