Increased C reactive protein and cardiac enzyme levels after coronary stent implantation. Is there protection by remote ischaemic preconditioning?

AIM

To investigate whether remote ischaemic preconditioning (RIPC) can attenuate the inflammatory response and enzyme leakage that can occur after uncomplicated routine percutaneous coronary intervention (PCI).

METHODS

41 consecutive normotensive patients with stable angina and single-vessel disease were assigned to be exposed to RIPC (n = 20) or not (control group; n = 21) before elective PCI with stent implantation. RIPC was induced by three cycles of 5-min ischaemia-reperfusion of both upper limbs (inflation/deflation of blood pressure cuff). C reactive protein (CRP), creatine phosphokinase (CK), CK cardiac isoenzyme (CK-MB) and troponin I (TNI) were serially measured for 48 h.

RESULTS

No difference in baseline values was observed between the groups. The CRP rose significantly (p<0.001) and at 48 h was similarly increased (>fourfold) in both groups (15.7 (2.6) v 14.0 (3.3) mg/l, RIPC v control; p = NS). However, sub-group analysis on the basis of statin use showed that the highest rise was in the group of patients with RIPC not taking statins and was significantly greater than in patients with RIPC taking statins (23.8 (3.71) v 11.4 (3.0) mg/l, respectively, p<0.01). Both CK-MB and TNI leakage were raised (slightly but significantly) after PCI in controls at 24 h compared with baseline values. However, this small rise was significantly worse after RIPC (CK-MB, 1.33 (0.27) v 3.57 (0.97) ng/ml, p<0.01; TNI, 0.255 (0.059) v 0.804 (0.232) ng/ml, p<0.05, respectively at 24 h). The increase was more marked in the RIPC subgroup not taking statins.

CONCLUSIONS

RIPC does not reduce, but exacerbates, the enzyme and TNI release from the heart after single-vessel angioplasty with stent. Furthermore, the increased circulating CRP remains raised. It seems that there is an enhanced inflammatory response after RIPC in the absence of statin treatment.

Effects of serial levosimendan infusions on left ventricular performance and plasma biomarkers of myocardial injury and neurohormonal and immune activation in patients with advanced heart failure

BACKGROUND

Levosimendan is a novel inodilator that improves central haemodynamics and symptoms of patients with decompensated chronic heart failure. The role, however, of repeated levosimendan infusions in the management of these patients has not yet been properly assessed.

PURPOSE

This randomised placebo-controlled trial investigated the effects of serial levosimendan infusions on cardiac geometry and function, and on biomarkers of myocardial injury and neurohormonal and immune activation (troponin T, N-terminal B-type natriuretic pro-peptide (NT-proBNP), C reactive protein (CRP) and interleukin (IL) 6) in patients with advanced heart failure.

METHODS

25 patients with decompensated chronic heart failure were randomised (2:1) to receive five serial 24-h infusions (every 3 weeks) of either levosimendan (n = 17) or placebo (n = 8), and were evaluated echocardiographically and biochemically before and after each drug infusion and 30 days after the final infusion.

RESULTS

Following treatment, cardiac end-systolic and end-diastolic dimension and volume indices were significantly reduced only in the levosimendan-treated patients (p<0.01). A significant decrease in NT-proBNP (p<0.01), high-sensitivity CRP (p<0.01) and plasma IL6 (p = 0.05) was also observed in the levosimendan group, whereas these markers remained unchanged in the placebo group; similar changes were observed after each drug infusion. Although the number of patients with a positive troponin T (>or=0.01 ng/ml) was not different between the two groups at baseline, it was significantly higher in the placebo-treated group during the final evaluation (p<0.05).

CONCLUSION

Serial levosimendan treatments improved left ventricular performance and modulated neurohormonal and immune activation beneficially in patients with advanced heart failure, without increasing myocardial injury.

Remote postconditioning is more potent than classic postconditioning in reducing the infarct size in anesthetized rabbits

PURPOSE

Postconditioning confers protection to the heart after a potentially lethal episode of prolonged ischemia. There is evidence that it may also be protective when applied at a distal artery. In the present study, we sought to determine whether remote postconditioning within the heart (local) or outside the heart (distal) is effective in salvaging the ischemic heart in vivo and to compare its effect with that of the classic postconditioning.

METHODS

Twenty seven open chest New Zealand white anesthetized male rabbits were divided into four groups and were exposed to 30 min regional myocardial ischemia (isc), after ligation of a prominent coronary artery, followed by 3 h reperfusion (rep) after releasing the snare. Control group (n = 7) was subjected to no additional interventions, postC group (n = 6) was subjected to four cycles of 1 min isc/1 min rep of the same coronary artery at the beginning of reperfusion, remote local postC group (n = 7) to four cycles of 1 min isc/1 min rep of another coronary artery 30 s before the end of index isc and remote distal postC group (n = 7) to four cycles of 1 min isc/1 min rep of another (carotid) artery again 30 s before the end of index isc. Infarct size (I) and area at risk (R) were delineated with the aid of TTC staining and green fluorescent microspheres respectively and their ratio was expressed in percent (%I/R).

RESULTS

Remote local and remote distal postC reduced the % I/R ratio (17.7 +/- 1.7% and 18.4 +/- 1.6%, respectively vs 47.0 +/- 2.5% in the control group, P < 0.01). Classic PostC had an intermediate protective effect (33.1 +/- 1.7%, P < 0.05 vs all the other groups).

CONCLUSION

Remote postconditioning consisted of 1 min isc/1 min rep protects the ischemic rabbit heart in vivo, independently of the site of the remote artery. This intervention seems to confer a stronger protection than the classic postconditioning.

Does passive leg raising increase cardiac performance? A study using Doppler echocardiography

Passive leg raising is commonly used for the initial treatment of hypovolemic shock. However, there are many reports which have pointed out that it does not produce significant autotransfusion effect. We tried to evaluate the effects of passive leg raising on the cardiovascular performance in coronary artery disease patients in stable condition. We studied 31 patients of 51 +/- 10 years. Two M-mode echocardiographic and continuous wave Doppler studies of aortic flow were obtained. The first was performed while the patient was lying on the left side and the second after passive leg elevation. Left ventricular end-diastolic dimension increased by 0.40 +/- 0.82 cm (P = 0.007), fractional shortening by 2.5 +/- 6% (P = 0.01), peak aortic blood velocity by 5 +/- 14 cm/s (P = 0.02), and velocity time integral by 1.7 +/- 3.0 cm (P = 0.0007). From the above it is concluded that passive leg elevation really does increase preload, and consequently cardiac performance, by the classical Frank-Staring relationship in normovolemic coronary artery disease patients.

Clinical and prognostic implications of self-rating depression scales and plasma B-type natriuretic peptide in hospitalised patients with chronic heart failure

BACKGROUND

Depression is common among patients with chronic heart failure (CHF) and has been independently associated with a poorer prognosis.

PURPOSE

This study evaluated the clinical and prognostic value of depression scales (Beck Depression Inventory (BDI), Zung Self-rating Depression Scale (Zung SDS)) along with plasma B-type natriuretic peptide (BNP) in CHF.

METHODS

155 hospitalised CHF patients (ejection fraction 26.9% (SD 6.4%)) were studied by depression (BDI, Zung SDS) and functional questionnaires (Kansas City Cardiomyopathy Questionnaire (KCCQ), Duke Activity Status Index (DASI)), BNP and 6-minute walk test (6MWT). Patients were followed for 6 months for cardiovascular events, including death from any cause or rehospitalisation for CHF decompensation.

RESULTS

Seventy-six (49%) patients with depressive symptoms, as estimated by both scales, had significantly lower DASI and KCCQ scores (13.2 (SD 9.9) vs 23.6 (SD 13.0) and 26.6 (SD 15.0) vs 45.0 (SD 17.0), respectively; p<0.001), higher BNP (921 (SD 889) vs 439 (SD 267) pg/ml, p = 0.001) and reduced 6MWT (270 (SD 130) vs 337 (SD 133); p<0.001). According to logistic regression analysis, Zung SDS and BNP were independently associated with adverse clinical outcomes; values of Zung SDS >or=40 and of BNP >or=290 pg/ml predicted future events with a sensitivity of 82% and 94% and a specificity of 45% and 46%, respectively. The combination of Zung SDS plus BNP had an additive prognostic value, predicting events with a sensitivity of 77% and a specificity of 70% (event-free survival: Zung <40 and BNP <290 pg/ml; 170 (SD 9) days; Zung >or=40 and BNP <290 pg/ml, 159 (SD 14) days; Zung <40 and BNP >or=290 pg/ml, 118 (SD 15) days; Zung >or=40 and BNP >or=290 pg/ml, 73 (SD 8) days, p<0.001).

CONCLUSIONS

CHF patients with depressive symptoms have impaired physical activity, associated with excessive neurohormonal activation. Among the studied scales, Zung SDS seemed to independently predict clinical outcome, especially in patients with increased plasma BNP concentration. Hence, the combination of those two modalities provides a practical means for risk stratification in CHF.

Dobutamine echocardiographic study in patients with nonischemic dilated cardiomyopathy and prognostically borderline values of peak exercise oxygen consumption: 18-month follow-up study

OBJECTIVES

We sought to study the prognostic value of dobutamine echocardiography in patients with nonischemic dilated cardiomyopathy (DCM) and prognostically borderline values of peak oxygen consumption (VO2max) during exercise.

BACKGROUND

Changes in echocardiographic variables assessed by dobutamine echocardiography can be used to evaluate the functional status of patients with chronic heart failure (CHF) and DCM.

METHODS

In 27 consecutive patients (mean age 55 +/- 15 years) with VO2max values between 10 and 14 ml/kg body weight per min, a low infusion rate (10 microg/kg per min) dobutamine echocardiographic test was performed. The induced changes in echocardiographic variables were measured, and an 18-month follow-up study was done.

RESULTS

At the end of the protocol, 9 patients (group I) had died from cardiac reasons, whereas the remaining 18 patients (group II) survived. After dobutamine infusion, the left ventricular end-systolic diameter (LVESD) was smaller in group II (6.22 +/- 0.94 cm) than in group I (6.99 +/- 0.76 cm; p < 0.05), whereas end-systolic wall stress (ESWS) was higher in group I (1030.66 +/- 193.98 g/cm2) than in group II (691.57 +/- 297.06 g/cm2; p < 0.05). The changes in LVESD and ESWS were greater in group I (0.75 +/- 0.36 cm and 463.11 +/- 159.87 g/cm2, respectively) than in group II (-0.04 +/- 0.36 cm and 83.16 +/- 291.74 g/cm2, respectively; p < 0.01 for both).

CONCLUSIONS

In the "gray" zone of VO2max, dobutamine echocardiography seems to be a valuable prognostic indicator in patients with CHF and DCM.

Painless myocardial ischemia in chronic hemodialysed patients: a real event?

We investigated the incidence of painless (silent) myocardial ischemia, manifested as S-T segment deviation, by Holter ECG monitoring in patients with chronic renal failure undergoing regular hemodialysis. Forty-five patients underwent Holter ECG monitoring for a continuous 48-hour period covering dialysis and the intermediate period of everyday activity at home. ECG criteria for ischemia were found in 15.5% of patients mainly during and immediately after dialysis with a simultaneous increase of R,S,R + S amplitude. There was no correlation of S-T segment deviation with the existence of cardiac dysfunction and coronary artery disease proved by hemodynamic and angiographic studies. It is concluded that hemodialysis itself seems to play an important role in the genesis of the above ECG findings, possibly by means of serum K and Mg changes.

Targeting the epigenome in malignant melanoma: Facts, challenges and therapeutic promises

Malignant melanoma is the most lethal type of skin cancer with high rates of mortality. Although current treatment options provide a short-clinical benefit, acquired-drug resistance highlights the low 5-year survival rate among patients with advanced stage of the disease. In parallel, the involvement of an aberrant epigenetic landscape, (e.g., alterations in DNA methylation patterns, histone modifications marks and expression of non-coding RNAs), in addition to the genetic background, has been also associated with the onset and progression of melanoma. In this review article, we report on current therapeutic options in melanoma treatment with a focus on distinct epigenetic alterations and how their reversal, by specific drug compounds, can restore a normal phenotype. In particular, we concentrate on how single and/or combinatorial therapeutic approaches have utilized epigenetic drug compounds in being effective against malignant melanoma. Finally, the role of deregulated epigenetic mechanisms in promoting drug resistance to targeted therapies and immune checkpoint inhibitors is presented leading to the development of newly synthesized and/or improved drug compounds capable of targeting the epigenome of malignant melanoma.

Assessment of the functional status of heart failure in non ischemic dilated cardiomyopathy: an echo-dobutamine study

BACKGROUND

The functional status of heart failure (HF) is conventionally evaluated by peak exercise oxygen consumption (VO2 max). Dobutamine echocardiography can be used to evaluate myocardial reserve. The aim of this study was to estimate the functional status of chronic HF in patients with dilated cardiomyopathy, by investigating the changes in echo-variables, as assessed by echo-dobutamine, in relation with VO2 max.

METHODS AND RESULTS

A low infusion rate echo-dobutamine test (10 micrograms/kg/min) was performed in 30 patients with dilated cardiomyopathy and 1 h later VO2 max was measured. VO2 max (ranging from 7.6 to 23 ml/kg/min, mean 14.06 +/- 0.64 ml/kg/min) was correlated with the changes (values obtained after inotropic stimulation minus those obtained at baseline) in left ventricular end-systolic diameter (r:0.80, p:0.001), in left ventricular end-systolic posterior wall thickness (r:0.73, p:0.001) and in left ventricular heart-rate corrected mean velocity of circumferential fiber shortening (Vcfc)/end-systolic meridional wall stress ratio (r:0.64, p:0.0001). A negative correlation was found between VO2 max and the changes in end-systolic meridional wall stress (r: -0.76, p:0.001). After dobutamine infusion Vcfc/systolic meridional wall stress ratio increased in patients with VO2 max > 14 ml/kg/min but decreased in patients with VO2 max < 14 ml/kg/min (0.0001 +/- 0.0001 vs -0.0002 +/- 0.0003 circ x cm2/g x s, p:0.0001). End-systolic meridional wall stress was decreased in patients with VO2 max > 14 ml/kg/min but increased in patients with VO2 max < 14 ml/kg/min (-126.97 +/- 34.24 vs 205.77 +/- 56.71 g/cm2, p:0.0001).

CONCLUSION

The changes in echo-variables assessed by echo-dobutamine are well correlated with VO2 max and seem to be accurate for evaluating the functional status of chronic HF in patients with dilated cardiomyopathy.

Clinical, adrenergic and heart endocrine measures in chronic atrial fibrillation as predictors of conversion and maintenance of sinus rhythm after direct current cardioversion

The aim of this study was to evaluate clinical, adrenergic and endocrine factors that could predict sinus rhythm maintenance after direct current cardioversion in chronic atrial fibrillation. Nineteen patients with chronic non-rheumatic atrial fibrillation (mean duration 6 +/- 5 months) were studied. They were exercised 24 h before cardioversion at maximum effort with the Naughton protocol. Heart rate and blood pressure at rest and exercise were recorded and blood samples were taken for the assessment of adrenergic activity, by measuring cyclic adenosine monophosphate, heart endocrine function, atrial natriuretic peptide and its second messenger, cyclic guanosine monophosphate. Fifteen of the 19 patients were initially converted to sinus rhythm (eight patients with external and seven patients with internal DC shocks). After 3 months eight patients remained in sinus rhythm and 11 had relapsed, most of them within the first month. On exercise the chronotropic response was lower in the group who remained in sinus rhythm than in the group in atrial fibrillation (peak heart rate 147 +/- 11 beats.min-1 vs 165 +/- 24 beats.min-1 P = 0.02). During exercise, the systolic blood pressure in the sinus group reached higher values than in the group who relapsed (192 +/- 17 mmHg vs 176 +/- 18 mmHg, P = 0.03). Cyclic adenosine monophosphate increased significantly from rest to peak exercise in the sinus rhythm group (from 23 +/- 9 pmol.ml-1 to 31 +/- 15 mol.ml-1, P = 0.02) while it remained unchanged in the atrial fibrillation group (25 +/- 10 pmol.ml-1 to 24 +/- 8 pmol.ml-1, P = 0.02). For all 19 patients the difference in cyclic adenosine monophosphate between rest and exercise was negatively correlated with maximum heart rate (r = 0.58, P = 0.009). Atrial natriuretic peptide increased from rest to peak exercise in the sinus rhythm group (from 129 +/- 58 fmol.ml-1 to 140 +/- 66 fmol.ml-1) while it remained unchanged in the group in which atrial fibrillation persisted or recurred (from 112 +/- 58 fmol.ml-1 to 111 +/- 53 fmol.ml-1, P = 0.002). A significant correlation between atrial natriuretic peptide and cyclic guanosine monophosphate levels at exercise before cardioversion was found for the sinus rhythm group only (r = 0.76, P = 0.02). In patients with non-rheumatic chronic atrial fibrillation evaluation of clinical parameters such as heart rate and blood pressure changes during maximal exercise can be useful in the choice of suitable therapy. An inadequate increase in plasma cyclic-adenosine monophosphate and atrial natriuretic peptide on exercise could predict patients with more severe underlying disease, where cardioversion should not be recommended.

Alterations in circulating cyclic guanosine monophosphate (c-GMP) during short and long ischemia in preconditioning

The aim of this study was to investigate if levels of circulating cyclic guanosine monophosphate (c-GMP) alter in preconditioning. Twenty-eight rabbits were divided into four groups. In vivo hearts were preconditioned, either with 5 min (group A, n = 8) or with 1 min (group B, n = 8) ischemia, followed by 10 min reperfusion, while groups C (n = 7) and D (n = 5) had no interventions. Protection was determined by subjecting groups A, B and C (but not D) to 30 min regional ischemia which was followed (including group D) by 2 h reperfusion. Seven blood samples were collected for the assessment of circulating c-GMP at different points of time. All results were expressed in pmol/ml using radio-immunoassay and the infarcted to risk area in percent using fluorescent particles and tetrazolium chloride (TTC). Circulating c-GMP increased during long ischemia only in group A (baseline value 47 +/- 4, long ischemic values 60.5 +/- 4 and 60.4 +/- 4, p < 0.05). Circulating c-GMP in group A was significantly higher in the middle of the long ischemia in comparison to the groups B, C and D (60.5 +/- 4 vs 43.9 +/- 4, 45.8 +/- 5 and 43.6 +/- 4, p < 0.05). Infarcted to risk ratio was lower in group A than in groups B and C (12.2 +/- 4 vs 29.6 +/- 6 and 34.2 +/- 6 respectively, p < 0.05). Circulating c-GMP is increased in classically preconditioned in comparison to ineffectively preconditioned hearts or to control groups. This elevation may be related to the protective effect of this phenomenon.

Pulmonary vein flow analysis by transoesophageal echocardiogr phy in patients with chronic atrial fibrillation; 1 year follow-up after cardioversion

AIMS

Left and right upper pulmonary vein flow can be adequately recorded by transoesophageal Doppler echocardiography. The aim of this study was to investigate whether analysis of the pulmonary venous flow velocity pattern can predict the long-term maintenance of sinus rhythm after successful cardioversion of chronic atrial fibrillation.

METHODS AND RESULTS

Thirty-six consecutive patients, aged 53+/-9 years, with chronic atrial fibrillation of 5.33+/-2 months duration, were subjected to transoesophageal Doppler echocardiography to record left and right upper pulmonary venous flow, 24 h and 3 months following successful cardioversion. One year following cardioversion, 12 patients (33.3%) were in sinus rhythm (sinus rhythm group) while the remaining 24 patients were in atrial fibrillation (atrial fibrillation group). At 24 h following cardioversion, biphasic systolic forward flow in the left and/or right upper pulmonary venous flow velocity was detected in 10 patients of the sinus rhythm group and in four patients of the atrial fibrillation group (P<0001). The systolic fraction was significantly higher in the sinus rhythm group, 0.48+/-0.04 and 0.39+/-0.06, P<0.001 for the left upper pulmonary venous flow, and 0.52+/-0.05 and 0.41+/-0.04, P<0.001 for the right upper pulmonary venous flow, respectively. In patients who displayed a biphasic systolic forward flow and in whom the right upper pulmonary venous flow systolic fraction was higher than 0.50 at 24 h post-cardioversion, the probability of maintenance of sinus rhythm at 1 year exceeded 95%.

CONCLUSION

The detection of a biphasic systolic forward flow in the pulmonary venous flow velocity, and of a right upper pulmonary vein systolic fraction higher than 0.50 as early as 24 h following cardioversion of chronic atrial fibrillation, identifies patients who will remain in sinus rhythm 1 year after cardioversion.

Coronary flow reserve assessed by transesophageal echocardiography identifies early restenosis of the left anterior descending coronary artery angioplasty

Although an increase in diastolic coronary flow velocity can be detected by transesophageal echocardiography 72 hours after both successful and unsuccessful left anterior coronary artery angioplasty, a significant improvement in coronary flow reserve is observed only in patients with a successful procedure. Transesophageal echocardiography-derived coronary flow reserve can identify early restenosis and thus serve as an index of the outcome of the procedure.

Transesophageal Doppler evaluation of left anterior descending coronary artery angioplasty

Transesophageal Doppler echocardiography can noninvasively evaluate the functional results of left anterior descending coronary artery angioplasty. Coronary flow reserve assessed by this technique is significantly increased only in those patients with less severe residual stenosis as detected by intravascular ultrasound, thus allowing a noninvasive assessment of the results of left anterior coronary artery angioplasty.

Serial evaluation of coronary flow reserve by transesophageal doppler echocardiography after angioplasty of proximal left anterior descending coronary artery: a 6-month follow-up study

BACKGROUND

Coronary flow reserve can be estimated by transesophageal Doppler echocardiography (TDE).

OBJECTIVE

To evaluate the coronary flow reserve by TDE, serially over 6 months' follow-up, after successful percutaneous transluminal coronary angioplasty (PTCA) of proximal left anterior descending coronary artery (LADA).

METHODS AND RESULTS

We performed TDE examination of 30 patients (mean age 55 +/- 9 years) 72 h, 3 months, and 6 months after PTCA of LADA. Selective angiography of LADA was repeated 72 h and 6 months after PTCA of LADA. Velocity of flow in LADA was measured before and 2 min after cessation of intravenous infusion of dipyridamole (0.56 mg/kg in 4 min). The dipyridamole: rest mean diastolic velocity ratio was considered as an index of coronary flow reserve (CFR). For 20 of 21 patients with CFR > 2 there was no restenosis, whereas coronary angiography revealed restenosis in eight of nine patients with CFR < 2. The sensitivity was 88.9% and the specificity was 95.2%. For the 21 patients without restenosis mean CFR was 2.1 +/- 0.1 72 h after PTCA, had increased to 3.1 +/- 0.3 (P < 0.0001) 3 months after PTCA, and remained stable thereafter (3.0 +/- 0.9).

CONCLUSION

CFR after PTCA of proximal LADA can be evaluated serially by transesophageal Doppler echocardiography. CFR of LADA in patients without restenosis is increased 3 months after PTCA and remains stable thereafter.

Prospective randomized trial of external versus internal transcatheter cardioversion in patients with chronic atrial fibrillation

To evaluate the safety and long-term efficacy of internal transcatheter cardioversion, forty patients with chronic, lone atrial fibrillation were studied. The patients were randomised to internal transcatheter cardioversion or to conventional external cardioversion. In cases where the procedure was unsuccessful, cross-over to the alternate method was performed. Oral anticoagulation therapy was started three weeks prior to the procedure and was maintained for another three weeks following successful cardioversion. Sinus rhythm was restored in 16/18 patients (88%) in the internal cardioversion group, versus 9/22 patients (40%) in the external cardioversion group (p < 0.01). In addition, 8/13 (61%) patients who were crossed-over to internal cardioversion were successfully cardioverted to sinus rhythm. In contrast, both patients who were crossed-over to external cardioversion remained in atrial fibrillation. During a mean follow-up period of 23 months, 13 (39.3%) patients maintained sinus rhythm. Using the intention to treat principle, the recurrence rate was not statistically different between the two methods. It is concluded that internal cardioversion is more effective in acutely restoring sinus rhythm compared to external cardioversion. However, both methods have similar long-term recurrence rates.

Decreased vasomotor effect of endothelin on the coronary arteries during angioplasty in hypertensive patients

To investigate if the response of the contralateral artery during coronary angioplasty (PTCA) is different in hypertensive than in normotensive patients and whether this response is related to plasma levels of endothelin-1 (ET-1). We examined the change in ET-1 plasma levels and the reactivity of the left circumflex artery (LCx) during PTCA of the left anterior descending branch in 10 hypertensive and 23 normotensive patients. Peripheral vein blood samples were drawn for ET-1 estimation at baseline, after the end of the first balloon inflation, at the end of PTCA, and 4 h later. Angiograms of the LCx were obtained at baseline and during the 1st balloon inflation. The ET-1 level in hypertensives increased from 6.81 +/- 3.76 at baseline to 7.54 +/- 4.76 pmol/l (P = n.s.) at the end of PTCA, while in normotensives it increased from 8.21 +/- 3.73 to 11.56 +/- 5.04 pmol/l (F = 7.48, P = 0.0002) respectively. The LCx distal segment diameter increased from 1.29 to 1.50 mm during balloon inflation in hypertensive, and from 1.44 to 1.53 mm (F = 5.03, P = 0.03) in normotensives. The diameter increase was related to the baseline ET-1 level (r = -0.67, P = 0.005) in the normotensives, but not in the hypertensives. Thus ET-1 has a weaker vasomotion effect on the coronary vasculature in hypertensives than in normotensives during PTCA.

Increased response of diastolic blood pressure to exercise in patients with coronary artery disease: an index of latent ventricular dysfunction?

OBJECTIVE

To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic function in patients with coronary artery disease.

DESIGN

Diastolic blood pressure was measured invasively during exercise stress testing and coronary angiograms and left ventriculograms were obtained at rest in patients with coronary artery disease. The abnormal (> or = 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular systolic function.

SETTING

Two tertiary referral centres.

PATIENTS

50 consecutive patients (mean age 57 years) with coronary artery disease.

MAIN OUTCOME MEASURES

The increase in diastolic blood pressure during exercise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries.

RESULTS

Group 1: 10 (20%) patients (three with one, four with two, and three with three vessel coronary artery disease) (mean (SD) age 54.7 (12) years) had an abnormal diastolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8.2) years) had a normal diastolic blood pressure response to stress testing. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) 1/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0.3) 1/min/m2 respectively, p < or = 0.001). The end systolic volume was greater in group 1 than in group 2: 38.7 (0.7 ml/m2 v 28.2 (2.1) ml/m2, p < or = 0.001.

CONCLUSION

In patients with coronary artery disease an abnormal increase in diastolic blood pressure during exercise stress testing correlated well with left ventricular systolic function at rest but not with the number of obstructed coronary arteries. The abnormal response of diastolic blood pressure probably reflects deterioration of myocardial function.

Protection from preconditioning can be reinstated at various reperfusion intervals

The aim of this study was to evaluate the way in which short-term protection declines and is eventually lost in preconditioning and to determine the efficacy of a second preconditioning at various reperfusion intervals. Male rabbits were divided into six groups. Forty-five minutes (sustained) ischemia followed by 120 minutes reperfusion was applied 60, 65, 70, 75, and 80 minutes after a 5 minute preconditioning (groups A, B, C, D, and E) and in a control group (F) after no preconditioning. The infarct to risk ratio (I/R) was 38.3 +/- 3.5% in group A, 46.0 +/- 7.8% in B, 61.6 +/- 9.7% in C, 68.1 +/- 4.2% in D, 64.5 +/- 7.8% in E, and 61.0 +/- 7.7% in F. Group A had a smaller I/R compared with groups C, D, E, and F (p < 0.05). In another series, groups G, H, and I were exposed to two 5-minute preconditioning stimuli, separated, respectively, by 45, 60, and 75 minutes of reperfusion; 10 minutes after the last preconditioning, the animals were exposed to 45-minutes ischemia and 120 minutes reperfusion. Groups A and D (with the smaller and higher I/R ratio) were also incorporated into this protocol in order to compare the effect of the additional preconditioning with the single one. The I/R ratio was 25.4 +/- 8.5% in group G, 22.8 +/- 7.0% in group H, and 14.7 +/- 4.0% in group I (p = NS). Group D showed a higher I/R compared with groups G, A, and H (p < 0.01), and group I had a smaller I/R compared with groups A (p < 0.01) and D (p < 0.001). Cardioprotection after a first preconditioning declines gradually and is eventually lost. An additional preconditioning is always effective, and the longer the interval from the first preconditioning, the more potent is the effect.

Coronary collateral blood-flow velocity improves with repeated coronary occlusions during angioplasty in patients with coronary artery disease and systemic hypertension

BACKGROUND

Cardiac hypertrophy is associated with numerous alterations in the coronary circulation.

OBJECTIVE

To test the hypothesis that, during angioplasty, the coronary collateral blood flow during repetitive coronary occlusions increases more in hypertensives than it does in normotensives.

METHODS

We studied 34 patients (22 normotensives and 12 hypertensives) with stable angina and single-vessel disease undergoing coronary angioplasty during two similar balloon inflations. Each balloon inflation was maintained for 120 s. The coronary blood flow velocity was estimated using the Doppler-flow guide wire, which was positioned distally to the lesion. Flow velocities were recorded before balloon deflation.

RESULTS

The average peak velocity increased by 29.0 +/- 14.7 mm/s in the hypertensives and decreased by 9.4 +/- 4.9 mm/s in the normotensives (P < 0.01) during the second balloon inflation, whereas the velocity-time integral increased by 33.1 +/- 19.2 mm and decreased by 14.3 +/- 11.3 mm (P < 0.05), respectively. The ST-segment elevation decreased by 1.13 +/- 1.27 and by 0.17 +/- 0.16 mV, respectively (P = 0.01). The increase in the average peak velocity which occurred during the second balloon inflation was related to the left ventricular mass (r = 0.47, P = 0.004).

CONCLUSION

These results indicate that the coronary collateral blood flow velocity improves with repetitive coronary occlusions during angioplasty in patients with systemic hypertension and that this increase is correlated to the left ventricular mass.