Domenico Lapenna

Intermittent antegrade warm blood cardioplegia

Intermittent antegrade warm blood cardioplegia has been used routinely at our institution over the last 3 years. We report here a comparison between the first 250 consecutive patients undergoing elective coronary artery bypass grafting in which intermittent antegrade warm blood cardioplegia was used (group A) and the last 250 consecutive patients who received intermittent antegrade cold blood cardioplegia, during bypass grafting (group B). There were no differences in sex, age, number of grafts, and functional status between the two groups; left ventricular ejection fraction was lower in group A. The overall mortality rate in group A was 0.8% versus 3.6% in group B (p < 0.05). There was no in-hospital mortality among high-risk patients (ejection fraction < or = 0.35) in group A (0/53) versus two deaths in group B (2/28) (p < 0.05). No patient in group A needed circulatory assistance; 4 patients in group B received intraaortic balloon pumping. Only 1 patient in group A required inotropic support versus 20 patients in group B (p < 0.0005), and 5 patients in group A received lidocaine hydrochloride for ventricular arrhythmias versus 18 in group B (p < 0.01). The rates of myocardial infarction and stroke were not different between the two groups. The peak concentration of the myocardial-specific isoenzyme of creatine kinase were higher in group B in absolute value (51 +/- 30 IU/L) than in Group A (38 +/- 38 IU/L) (p < 0.0005) and in percent of total creatine kinase (8.2% +/- 4.1% versus 6.2% +/- 2.9%, respectively).

Vitamins E, C and lipid peroxidation in plasma and arterial tissue of smokers and non-smokers

An imbalance between pro-oxidants and antioxidants is operative in atherosclerosis. Cigarette smoke is a major risk factor of atherosclerosis and has been reported to contain large amounts of oxidants. We assessed arterial (internal mammary artery) and plasma levels of vitamins E and C and lipid peroxides in 48 male patients, 24 smokers and 24 non-smokers, undergoing coronary bypass surgery. Lipid peroxidation was studied using fluorescent products of lipid peroxidation (FPLs). Tissue vitamins E and C levels were significantly lower and FPLs significantly higher in smokers than in non-smokers (P < 0.0006, 0.0005 and 0.0005, respectively). This pattern was associated with lower vitamin C and higher lipid peroxide plasma levels in smokers than in non-smokers (P < 0.0002 and 0.0005, respectively). Vitamins E and C plasma levels were strongly related to their tissue content both in smokers (r = 0.60, P < 0.005 and r = 0.57, P < 0.01) and in non-smokers (r = 0.42, P < 0.05 and r = 0.46, P < 0.05). Moreover, vitamin E content was significantly related to that of vitamin C only in the arterial tissue of both groups, pointing to the existence of a functional interaction between these antioxidants. In both groups, FPLs were significantly and inversely related to vitamin C in plasma and to vitamin E in tissue, suggesting the antioxidant primary of vitamin C and vitamin E in the plasma and arterial tissue compartments, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic Value of Different Indices of Blood Pressure Variability in Hypertensive Patients

BACKGROUND The independent prognostic significance of different indices of blood pressure (BP) variability is not clear. We investigated the prognostic value of BP variability estimated as s.d. or average real variability (ARV) of daytime and night time BP, in hypertensive patients. METHODS The occurrence of fatal and nonfatal cardiovascular events was evaluated in 1,280 sequential hypertensive patients (550 initially untreated and 730 initially treated) aged > or =40 years. Subjects with s.d. or ARV of daytime or night time systolic or diastolic BP below or above the median were classified as having low or high BP variability. RESULTS During the follow-up (4.75 +/- 1.8 years), 104 cardiovascular events occurred. The event rate per 100 patient-years was 1.71 in the global population. After adjustment for other covariates, Cox regression analysis showed that cardiovascular risk was higher in subjects with high ARV of daytime systolic BP in initially untreated, initially treated, and all the subjects (high vs. low ARV, hazard ratio (HR) 2.29 (1.06-4.94), HR 1.90 (1.06-3.39), and HR 2.07 (1.31-3.28), respectively). ARV of daytime diastolic BP and night time BP, and s.d. of daytime and night time BP were not significantly associated with risk or were not independent predictors of outcome. CONCLUSIONS In this study, high ARV of daytime systolic BP resulted in an independent predictor of cardiovascular risk in hypertensive patients, while high s.d. did not. Our data suggest that, in comparison to s.d., ARV could be a more appropriate index of BP variability and a more useful predictor of outcomes.

Glutathione-Related Antioxidant Defenses in Human Atherosclerotic Plaques

BACKGROUND Oxidative stress, resulting from an antioxidant/prooxidant imbalance, seems to be crucial in atherogenesis. Recent evidence has emerged, however, of a surprisingly high content of low-molecular-weight antioxidants in human atherosclerotic plaques, although other antioxidant systems have not been investigated in these lesions. METHODS AND RESULTS We studied glutathione-related antioxidant defenses (which play a key role in tissue antioxidant protection) in carotid atherosclerotic plaques of 13 patients subjected to endarterectomy and in normal internal mammary arteries of 13 patients undergoing coronary artery bypass surgery. Selenium-dependent glutathione peroxidase activity was undetectable in the plaques of 7 patients; the other 6 patients with plaques showed a mean enzymatic activity approximately 3.5-fold lower than that of mammary arteries. Glutathione reductase activity was also markedly lower in the plaques than in the arteries. Glutathione transferase instead had comparable activity in the two tissues. Remarkably, 5 of the 7 patients with an undetectable selenium-dependent glutathione peroxidase activity but none of the 6 with a detectable one were characterized by multivascular atherosclerotic involvement (3 patients) or stenosis of the contralateral carotid artery (2 patients). CONCLUSIONS A weak glutathione-related enzymatic antioxidant shield is present in human atherosclerotic lesions. Although the cause of this phenomenon remains to be determined, the present data suggest that a specific antioxidant/prooxidant imbalance operative in the vascular wall may be involved in atherogenic processes in humans.

Reaction conditions affecting the relationship between thiobarbituric acid reactivity and lipid peroxidesin human plasma

The thiobarbituric acid (TBA) reactivity of human plasma was studied to evaluate its adequacy in quantifying lipid peroxidation as an index of systemic oxidative stress. Two spectrophotometric TBA tests based on the use of either phosphoric acid (pH 2.0, method A) or trichloroacetic plus hydrochloric acid (pH 0.9, method B) were employed with and without sodium sulfate (SS) to inhibit sialic acid (SA) reactivity with TBA. To correct for background absorption, the absorbance values at 572 nm were subtracted from those at 532 nm, which represent the absorption maximum of the TBA:MDA adduct. Method B gave values of TBA-reactive substances (TBARS) 2-fold higher than those detected with method A. SS lowered TBARS by about 50% with both methods, indicating a significant involvement of SA in plasma TBA reactivity. Standard SA, at a physiologically relevant concentration of 1.5 mM, reacted with TBA, creating interference problems, which were substantially eliminated by SS plus correction for background absorbance. When method B was carried out in the lipid and protein fraction of plasma, SS inhibited by 65% TBARS formation only in the latter. Protein TBARS may be largely ascribed to SA-containing glycoproteins and, to a minor extent, protein-bound MDA. Indeed, EDTA did not affect protein TBARS assessed in the presence of SS. TBA reactivity of whole plasma and of its lipid fraction was instead inhibited by EDTA, suggesting that lipoperoxides (and possibly monofunctional lipoperoxidation aldehydes) are involved as MDA precursors in the TBA test. Pretreatment of plasma with KI, a specific reductant of hydroperoxides, decreased TBARS by about 27%. Moreover, aspirin administration to humans to inhibit prostaglandin endoperoxide generation reduced plasma TBARS by 40%. In conclusion, reaction conditions affect the relationship between TBA reactivity and lipid peroxidation in human plasma. After correction for the interfering effects of SA in the TBA test, 40% of plasma TBARS appears related to in vivo generated prostaglandin endoperoxides and only about 60% to lipoperoxidation products. Thus, the TBA test is not totally specific to oxidant-driven lipid peroxidation in human plasma.

Aortic antioxidant defence mechanisms: time-related changes in cholesterol-fed rabbits

In 24 rabbits fed a hyperlipidic diet (0.5% cholesterol, 5% lard and 5% peanut oil) for 10 (group A1), 30 group B1) and 60 days, (Group C1), compared to 24 control rabbits fed a standard diet for the same periods, antioxidant defence system (total superoxide dismutase, catalase, total thiol compounds selenium-dependent and selenium-independent glutathione peroxidase, glutathione reductase, glutathione transferase) and lipid peroxidation (thiobarbituric acid-reactive substances) in the aortic wall were tested. The percent of intima with grossly apparent atherosclerosis, is assessed by staining with the lipophilic dye Sudan IV, was negligible in group A1, but increased progressively in groups B1 (22.7-6.7%) and C1 (56.8-8.8%). Compared to the controls, a significant rise in superoxide dismutase activity was observed after 30 days of hyperlipidic diet, with a further marked increase at 60 days. Total thiol compounds and selenium-dependent glutathione peroxidase activity rose progressively from 10 to 30 and 60 days in cholesterol-fed rabbits. On the contrary, catalase, glutathione reductase and glutathione transferase activities significantly decreased in all experimental groups. Selenium-independent glutathione peroxidase activity was not detectable. Thiobarbituric acid-reactive substances increased about 3 times in hyperlipidemic rabbits. In conclusion, the changes in aortic antioxidant defence mechanisms and lipid peroxidation precede the massive vascular lipid infiltration in cholesterol-fed rabbits; some antioxidant mechanisms are stressed (superoxide, dismutase, glutathione peroxidase, total thiol compounds), whereas others are depressed (catalase, glutathione reductase, and glutathione transferase), thus potentially reducing or increasing vascular susceptibility to oxidative injury.

Target Organ Status and Serum Lipids in Patients With White Coat Hypertension

Target organ status and serum lipids were investigated in white coat hypertension in comparison with sustained hypertension and normotension. We selected three groups balanced for sex, age, body mass index, and smoking habit: 50 sustained hypertensives (clinical hypertension and 24-hour ambulatory blood pressure > 135/85 mm Hg, a cutoff limit obtained from a normotensive population), 25 white coat hypertensives (clinical hypertension and 24-hour ambulatory blood pressure < 135/85 mm Hg), and normotensives. Subjects underwent echocardiographic examinations to assess left ventricular mass index, carotid ultrasonography to evaluate intima-media thickness and atherosclerotic plaques, venous occlusion plethysmography to record minimum forearm vascular resistance, and determinations of serum lipid profile and 24-hour urinary albumin excretion. Compared with sustained hypertensives, the white coat hypertensives had significantly lower values of left ventricular mass index (125.9 +/- 20 versus 97.6 +/- 11.5 g/m2, P < .05, intima-media thickness (0.85 +/- 0.18 versus 0.71 +/- 0.15 mm, P < .05), minimum forearm vascular resistance (2.33 +/- 0.11 versus 2.04 +/- 0.08 resistance units, P < .05), urinary albumin excretion values (15.1 +/- 13.8 versus 4.45 +/- 1.48 mg per 24 hours, P < .0001), prevalence of left ventricular hypertrophy (versus 4%, P < .002), intima-media thickening 28% versus 4%, P < .015), and microalbuminuria (22% versus 0%, P < .015). No significant difference, however, was observed between the white coat hypertensives and the normotensives. Serum lipid profile was similar in the white coat hypertensives and in the normotensives.(ABSTRACT TRUNCATED AT 250 WORDS)

Endogenous ouabain and hemodynamic and left ventricular geometric patterns in essential hypertension

We sought to evaluate the relationships among circulating levels of an endogenous ouabain-like factor (EO) and systemic hemodynamics and left ventricular (LV) geometry in patients with recently diagnosed essential hypertension. We selected 92 never-treated patients with essential hypertension. Blood samples were drawn for estimation of plasma EO (radioimmunoassay) and subjects underwent echocardiographic examination to evaluate LV end-systolic and end-diastolic wall thickness and internal dimensions. LV volumes, stroke volume, cardiac output, total peripheral resistance, LV mass, and relative wall thickness were calculated, and all except the last parameter were indexed by body surface area. LV mass also was indexed by height. On the basis of the values of LV mass index (body surface area or height) and relative wall thickness, subjects were divided into groups with either normal geometry, concentric remodeling, concentric hypertrophy, or eccentric nondilated hypertrophy. In the study population as a whole, circulating EO levels were significantly and directly correlated with mean blood pressure (r = 0.21, P = .048), relative wall thickness (r = 0.34, P = .001), and total peripheral resistance index (r = 0.37, P = .0003). Plasma EO also was significantly and inversely correlated with LV end-diastolic volume index (r = -0.32, P = .002), stroke index (r = -0.34, P = .0009), and cardiac index (r = -0.35, P = .0007). In multiple regression analysis, plasma EO was an independent correlate of total peripheral resistance index, cardiac index, and relative wall thickness. Regardless of the indexation method used for LV mass, plasma EO was higher in patients with concentric remodeling than in those with either normal geometry or concentric hypertrophy. Plasma EO tended to be higher (indexation by body surface area) or was significantly higher (indexation by height) in subjects with concentric remodeling than in those with eccentric nondilated hypertrophy. Patients with concentric remodeling showed the highest total peripheral resistance index and the lowest cardiac index. Our data suggest that EO plays a role in regulating systemic hemodynamics and LV geometry in patients with essential hypertension.

Viscero-visceral hyperalgesia: characterization in different clinical models.

&NA; Co‐existing algogenic conditions in two internal organs in the same patient may mutually enhance pain symptoms (viscero‐visceral hyperalgesia). The present study assessed this phenomenon in different models of visceral interaction. In a prospective evaluation, patients with: (a) coronary artery disease (CAD) + gallstone (Gs) (common sensory projection: T5); (b) irritable bowel syndrome (IBS) + dysmenorrhea (Dys) (T10‐L1); (c) dysmenorrhea/endometriosis + urinary calculosis (Cal)(T10‐L1); and (d) gallstone + left urinary calculosis (Gs + LCal) (unknown common projection) were compared with patients with CAD, Gs, IBS, Dys or Cal only, for spontaneous symptoms (number/intensity of pain episodes) over comparable time periods and for referred symptoms (muscle hyperalgesia; pressure/electrical pain thresholds) from each visceral location. In patients’ subgroups, symptoms were also re‐assessed after treatment of each condition or after no treatment. (a) CAD + Gs presented more numerous/intense angina/biliary episodes and more referred muscle chest/abdominal hyperalgesia than CAD or Gs; cardiac revascularization or cholecystectomy also reduced biliary or cardiac symptoms, respectively (0.001 < p < 0.05). (b) IBS + Dys had more intestinal/menstrual pain and abdomino/pelvic muscle hyperalgesia than IBS or Dys; hormonal dysmenorrhea treatment also reduced IBS symptoms; IBS dietary treatment also improved dysmenorrhea (0.001 < p < 0.05) while no treatment of either conditions resulted in no improvement in time of symptoms from both. (c) Cal + Dys had more urinary/menstrual pain and referred lumbar/abdominal hyperalgesia than Cal or Dys; hormonal dysmenorrhea treatment/laser treatment for endometriosis also improved urinary symptoms; lithotripsy for urinary stone also reduced menstrual symptoms (0.001 < p < 0.05). (d) In Gs + LCal, cholecystectomy or urinary lithotripsy did not improve urinary or biliary symptoms, respectively. Mechanisms of viscero‐visceral hyperalgesia between organs with documented partially common sensory projection probably involve sensitization of viscero‐viscero‐somatic convergent neurons.

Influence of endometriosis on pain behaviors and muscle hyperalgesia induced by a ureteral calculosis in female rats.

&NA; Endometriosis and urinary calculosis can co‐occur. Clinical studies have shown that both painful and non‐painful endometriosis in women are associated with enhanced pain and referred muscle hyperalgesia from urinary calculosis, but the mechanisms underlying this phenomenon are still poorly understood. The aim of this study was to develop an animal model adequate to explore this viscero‐visceral interaction in standardized conditions. Using a model of endometriosis previously developed to study reduced fertility and vaginal hyperalgesia, endometriosis (endo) or sham‐endometriosis (sham‐endo) was induced in rats by autotransplantation of small pieces of uterus (or, for sham‐endo, fat) on cascade mesenteric arteries, ovary, and abdominal wall. After the endometrial, but not the fat autografts had produced fluid‐filled cysts (3 weeks), urinary calculosis was induced by implanting an artificial stone into one ureter. Pain behaviors were monitored by continuous 24‐h videotape recordings before and after stone implantation. Referred muscle hyperalgesia was assessed by measuring vocalization thresholds to electrical stimulation of the oblique musculature (L1 dermatome). The data were compared with previously reported data from rats that had received only the stone. Neither endo nor sham‐endo alone induced pain behaviors. Following stone implantation, in endo rats compared to sham‐endo and stone‐only rats, pain behaviors specifically associated with urinary calculosis were significantly increased and new pain behaviors specifically associated with uterine pathology became evident. Muscle hyperalgesia was also significantly increased. To explore the relationship between the amount of endometriosis and that of ureteral pain behavior, two separate groups of endo rats were treated with either a standard non‐steroidal anti‐inflammatory drugs (ketoprofen) or placebo from the 12th to the 18th day after endometriosis induction. The stone was implanted on the 21st day. Ketoprofen treatment compared to placebo significantly reduced the size of the cysts and both ureteral and uterine pain behaviors post‐stone implantation. The size of the cysts showed a significant linear correlation with the post‐stone ureteral pain behaviors. In conclusion, endo increased pain crises and muscle hyperalgesia typically induced by a ureteral calculosis, and the ureteral calculosis revealed additional pain behaviors typically induced by uterine pathophysiology; and this enhancement was a function of the degree of endometriosis. This result closely reproduces the condition observed in humans and could be due to a phenomenon of ‘viscero‐visceral’ hyperalgesia, in which increased input from the cyst implantation sites to common spinal cord segments (T10‐L1) facilitates the central effect of input from the urinary tract.