Usefulness of Nisoldipine for prevention of restenosis after percutaneous transluminal coronary angioplasty (results of the NICOLE study). NIsoldipine in COronary artery disease in LEuven

Myocardin-Dependent Kv1.5 Channel Expression Prevents Phenotypic Modulation of Human Vessels in Organ Culture

Objective:

We have previously described that changes in the expression of Kv channels associate to phenotypic modulation (PM), so that Kv1.3/Kv1.5 ratio is a landmark of vascular smooth muscle cells phenotype. Moreover, we demonstrated that the Kv1.3 functional expression is relevant for PM in several types of vascular lesions. Here, we explore the efficacy of Kv1.3 inhibition for the prevention of remodeling in human vessels, and the mechanisms linking the switch in Kv1.3 /Kv1.5 ratio to PM.

Approach and Results:

Vascular remodeling was explored using organ culture and primary cultures of vascular smooth muscle cells obtained from human vessels. We studied the effects of Kv1.3 inhibition on serum-induced remodeling, as well as the impact of viral vector-mediated overexpression of Kv channels or myocardin knock-down. Kv1.3 blockade prevented remodeling by inhibiting proliferation, migration, and extracellular matrix secretion. PM activated Kv1.3 via downregulation of Kv1.5. Hence, both Kv1.3 blockers and Kv1.5 overexpression inhibited remodeling in a nonadditive fashion. Finally, myocardin knock-down induced vessel remodeling and Kv1.5 downregulation and myocardin overexpression increased Kv1.5, while Kv1.5 overexpression inhibited PM without changing myocardin expression.

Conclusions:

We demonstrate that Kv1.5 channel gene is a myocardin-regulated, vascular smooth muscle cells contractile marker. Kv1.5 downregulation upon PM leaves Kv1.3 as the dominant Kv1 channel expressed in dedifferentiated cells. We demonstrated that the inhibition of Kv1.3 channel function with selective blockers or by preventing Kv1.5 downregulation can represent an effective, novel strategy for the prevention of intimal hyperplasia and restenosis of the human vessels used for coronary angioplasty procedures.

The effects of calcium channel blockers in the prevention of stroke in adults with hypertension: a meta-analysis of data from 273,543 participants in 31 randomized controlled trials

BACKGROUND

Hypertension is a major risk factor for the development of stroke. It is well known that lowering blood pressure decreases the risk of stroke in people with moderate to severe hypertension. However, the specific effects of calcium channel blockers (CCBs) against stroke in patients with hypertension as compared to no treatment and other antihypertensive drug classes are not known.

METHODS AND FINDINGS

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CCBs effect on stroke in patients with hypertension in studies of CCBs versus placebo, angiotensin-converting-enzyme inhibitors (ACEIs), β-adrenergic blockers, and diuretics. The PUBMED, MEDLINE, EMBASE, OVID, CNKI, MEDCH, and WANFANG databases were searched for trials published in English or Chinese during the period January 1, 1996 to July 31, 2012. A total of 177 reports were collected, among them 31 RCTs with 273,543 participants (including 130,466 experimental subjects and 143,077 controls) met the inclusion criteria. In these trials a total of 9,550 stroke events (4,145 in experimental group and 5,405 in control group) were reported. CCBs significantly decreased the incidence of stroke compared with placebo (OR = 0.68, 95% CI 0.61-0.75, p<1×10(-5)), β-adrenergic blockers combined with diuretics (OR = 0.89, 95% CI 0.83-0.95, p = 7×10(-5)) and β-adrenergic blockers (OR = 0.79, 95% CI 0.72-0.87, p<1×10(-5)), statistically significant difference was not found between CCBs and ACEIs (OR = 0.92, 95% CI 0.8-1.02, p = 0.12) or diuretics (OR = 0.95, 95% CI 0.84-1.07, p = 0.39).

CONCLUSION

In a pooled analysis of data of 31 RCTs measuring the effect of CCBs on stroke, CCBs reduced stroke more than placebo and β-adrenergic blockers, but were not different than ACEIs and diuretics. More head to head RCTs are warranted.

The effects of blood pressure reduction and of different blood pressure-lowering regimens on major cardiovascular events according to baseline blood pressure: meta-analysis of randomized trials

BACKGROUND

The benefits of reducing blood pressure are well established, but there remains uncertainty about whether the magnitude of the effect varies with the initial blood pressure level. The objective was to compare the risk reductions achieved by different blood pressure-lowering regimens among individuals with different baseline blood pressures.

METHODS

Thirty-two randomized controlled trials were included and seven comparisons between different types of treatments were made. For each comparison, the primary prespecified analysis included calculation of summary estimates of effect using random-effects meta-analysis for major cardiovascular events in four groups defined by baseline SBP (<140, 140-159, 160-179, and ≥ 180 mmHg).

RESULTS

There were 201 566 participants among whom 20 079 primary outcome events were observed. There was no evidence of differences in the proportionate risk reductions achieved with different blood pressure-lowering regimens across groups defined according to higher or lower levels of baseline SBP (all P for trend > 0.17). This finding was broadly consistent for comparisons of different regimens, for DBP categories, and for commonly used blood pressure cut-points.

CONCLUSION

It appears unlikely that the effectiveness of blood pressure-lowering treatments depends substantively upon starting blood pressure level. As the majority of patients in the trials contributing to these overviews had a history of hypertension or were receiving background blood pressure-lowering therapy, the findings suggest that additional blood pressure reduction in hypertensive patients meeting initial blood pressure targets will produce further benefits. More broadly, the data are supportive of the utilization of blood pressure-lowering regimens in high-risk patients with and without hypertension.

Do men and women respond differently to blood pressure-lowering treatment? Results of prospectively designed overviews of randomized trials

AIMS

Large-scale observational studies show that lower blood pressure is associated with lower cardiovascular risk in both men and women although some studies have suggested that different outcomes between the sexes may reflect different responses to blood pressure-lowering treatment. The aims of these overview analyses were to quantify the effects of blood pressure-lowering treatment in each sex and to determine if there are important differences in the proportional benefits of treatment between men and women.

METHODS AND RESULTS

Thirty-one randomized trials that included 103,268 men and 87,349 women contributed to these analyses. For each outcome and each comparison summary estimates of effect and 95% confidence intervals were calculated for men and women using a random-effects model. The consistency of the effects of each treatment regimen across the sexes was examined using chi(2) tests of homogeneity. Achieved blood pressure reductions were comparable for men and women in every comparison made. For the primary outcome of total major cardiovascular events there was no evidence that men and women obtained different levels of protection from blood pressure lowering or that regimens based on angiotensin-converting-enzyme inhibitors, calcium antagonists, angiotensin receptor blockers, or diuretics/beta-blockers were more effective in one sex than the other (all P-homogeneity > 0.08).

CONCLUSION

All of the blood pressure-lowering regimens studied here provided broadly similar protection against major cardiovascular events in men and women. Differences in cardiovascular risks between sexes are unlikely to reflect differences in response to blood pressure-lowering treatments.

Calcium channel antagonists reduce restenosis after percutaneous transluminal angioplasty of an arteriovenous fistula in hemodialysis patients

Percutaneous transluminal angioplasty (PTA) for stenosis of hemodialysis fistulas is associated with a high incidence of restenosis, and improvement of the patency rate after PTA is greatly needed. In addition, angiotensin II receptor blockers (ARB), calcium channel antagonists (CCA) and antiplatelet agents (APA) are commonly administered to most hemodialysis patients. This study retrospectively examined the effect of these medications on the incidence of restenosis after angioplasty for hemodialysis fistulae. The subjects were 92 patients--54 with anastomotic stenosis of an arteriovenous fistula (AVF) and 38 with stenosis of the draining veins of an arteriovenous graft (AVG)--who underwent angioplasty between January 2001 and December 2003. The patency period was defined as the interval from the first to the second angioplasty or surgical reconstruction. We excluded patients who received angioplasty two or more times. The effect of each drug on the patency of the AVF or AVG was assessed by the Kaplan-Meier method with the log-rank test and multiple logistic regression analysis. The group receiving CCA therapy showed a higher patency rate for both an AVF and an AVG. Although multiple logistic regression analysis also showed that a CCA reduces restenosis independently in an AVF, there was no significant correlation between a CCA and patency in an AVG. Treatment with an ARB and an APA was not associated with significantly higher patency rates for either an AVF or AVG. A CCA may reduce the incidence of restenosis after percutaneous intervention for stenosis of an AVF.

Rationale and public health implications of changing CHD risk factor definitions

The definition of disease is central to the practice of medicine and to public health policy. Practice guidelines set standards for disease identification and treatment. Quality care is often defined as adherence to these guidelines. Over the past few years, the diagnostic thresholds for several common medical conditions have been lowered, resulting in a substantial expansion in the market for health care. The most recent guidelines for high blood pressure, high cholesterol, and impaired fasting glucose each define a high percentage of the adult population as in need of regular medical attention. Under the latest proposed thresholds, virtually the entire adult population qualifies for a chronic condition diagnosis. We evaluate the health and financial outcomes associated with changes in diagnostic thresholds for the prevention of three risk factors for cardiovascular disease and stroke: blood pressure, serum cholesterol, and fasting plasma glucose. Estimates of the numbers of people affected, the cost implications, and the overall public health consequences are offered.

Calcium channel blockers in the spectrum of antihypertensive agents

Calcium channel blockers (CCBs) are widely used in the treatment of hypertension. Through blood pressure reduction, and possibly other mechanisms such as antioxidative effects, they may play a role in diminishing the risk for a variety of cardiovascular outcomes. The combination of CCBs with other newer antihypertensive agents such, as ACE inhibitors and angiotensin receptor blockers, may provide complementary effects on risk reduction in cardiovascular adverse events and renal disease. Although the efficacy of CCBs as antihypertensive agents has been adequately demonstrated, there have been concerns regarding the use of short acting dihydropyridines after acute myocardial infarction. There have also been questions about the role of CCBs with regards to other antihypertensive agents in renal disease. For example, differential effects of dihydropyridine and non-dihydropyridine CCBs may affect progression of renal disease and risk for diabetes. Certain precautions involving drug interactions are needed because of the effects of CCBs on the CYP450 enzyme systems.

Blood Pressure Reduction and Cardiovascular Prevention: An Update Including the 2003-2004 Secondary Prevention Trials

In a meta-analysis published in June 2003, we reported that new and old classes of antihypertensive drugs had similar long-term efficacy and safety. Furthermore, we observed that in clinical trials in hypertensive or high-risk patients gradients in systolic blood pressure (SBP) accounted for most differences in outcome. To test whether our previous conclusions would hold, we updated our quantitative overview with new information from clinical trials published before 2005. To compare new and old antihypertensive drugs, we computed pooled odds ratios from stratified 2 x 2 contingency tables. In a meta-regression analysis, we correlated these odds ratios with corresponding between-group differences in SBP. We then contrasted observed odds ratios with those predicted from gradients in SBP. The main finding of our overview was that reduction in SBP largely explained cardiovascular outcomes in the recently published actively controlled trials in hypertensive patients and in placebo-controlled secondary prevention trials. The published results suggested that dihydropyridine calcium-channel blockers might offer a selective benefit in the prevention of stroke and inhibitors of the renin-angiotensin system in the prevention of heart failure. For prevention of myocardial infarction, the published results were more equivocal, because of the benefit of amlodipine over placebo or valsartan in 2 trials, whereas other placebo-controlled trials of calcium-channel blockers or angiotensin converting enzyme inhibitors did not substantiate the expected benefit with regard to cardiac outcomes. In conclusion, the hypothesis that new antihypertensive drugs might influence cardiovascular prognosis over and beyond their antihypertensive effect remains unproven. Our overview emphasizes the need of tight blood pressure control, but does not allow determining to what extent blood pressure must be lowered for optimal cardiovascular prevention.

Effects of different blood-pressure-lowering regimens on major cardiovascular events: results of prospectively-designed overviews of randomised trials

BACKGROUND

The benefits of reducing blood pressure on the risks of major cardiovascular disease are well established, but uncertainty remains about the comparative effects of different blood-pressure-lowering regimens. We aimed to estimate effects of strategies based on different drug classes (angiotensin-converting-enzyme [ACE] inhibitors, calcium antagonists, angiotensin-receptor blockers [ARBs], and diuretics or beta blockers) or those targeting different blood pressure goals, on the risks of major cardiovascular events and death.

METHODS

We did seven sets of prospectively-designed overviews with data from 29 randomised trials (n=162341). The trial eligibility criteria, primary outcomes, and main hypotheses were specified before the result of any contributing trial was known.

FINDINGS

In placebo-controlled trials the relative risks of total major cardiovascular events were reduced by regimens based on ACE inhibitors (22%; 95% CI 17-27) or calcium antagonists (18%; 5-29). Greater risk reductions were produced by regimens that targeted lower blood pressure goals (15%; 5-24). ARB-based regimens reduced the risks of total major cardiovascular events (10%; 4-17) compared with control regimens. There were no significant differences in total major cardiovascular events between regimens based on ACE inhibitors, calcium antagonists, or diuretics or beta blockers, although ACE-inhibitor-based regimens reduced blood pressure less. There was evidence of some differences between active regimens in their effects on cause-specific outcomes. For every outcome other than heart failure, the difference between randomised groups in achieved blood pressure reduction was directly related to the observed difference in risk.

INTERPRETATION

Treatment with any commonly-used regimen reduces the risk of total major cardiovascular events, and larger reductions in blood pressure produce larger reductions in risk.

Long term effects of nisoldipine on the progression of coronary atherosclerosis and the occurrence of clinical events: the NICOLE study

BACKGROUND

Earlier angiographic studies have suggested that calcium antagonists may prevent the formation of new coronary lesions and the progression of minimal lesions. Conversely, a meta-analysis suggested that these drugs may increase cardiovascular mortality and morbidity in patients with coronary heart disease.

OBJECTIVE

To investigate whether nisoldipine retards the progression of coronary atherosclerosis or reduces the occurrence of clinical events.

DESIGN AND SETTING

The NICOLE study (NIsoldipine in COronary artery disease in LEuven) is a single centre, randomised, double blind, placebo controlled trial with coronary angiography at baseline, six months, and three years of follow up.

PATIENTS

826 patients who had undergone successful coronary angioplasty were randomised to nisoldipine 40 mg once daily or placebo. The intention to treat and per protocol population consisted of 819 and 578 patients, respectively.

RESULTS

In the per protocol population, 625 of the nisoldipine treated and 655 of the placebo treated patients (NS) showed angiographic progression in at least one coronary arterial segment, defined as an increase in diameter stenosis of > or = 13%. The average minimum luminal diameter of the non-dilated lesions decreased by 0.163 mm and 0.167 mm in the nisoldipine and placebo groups, respectively (NS). The respective numbers of new lesions detected were 7 and 13 (NS). In the intention to treat population, the rates of death, stroke, and acute myocardial infarction were similar in both treatment groups. However, nisoldipine use was associated with fewer revascularisation procedures and thus the percentage of patients with any clinical event was lower (44.6% v 52.6%, p = 0.02).

CONCLUSIONS

Nisoldipine has no demonstrable effect on the angiographic progression of coronary atherosclerosis or the risk of major cardiovascular events but its use is associated with fewer revascularisation procedures.

Effects of amlodipine on ischemia after percutaneous transluminal coronary angioplasty: secondary results of the Coronary Angioplasty Amlodipine Restenosis (CAPARES) Study

BACKGROUND

Despite successful coronary angioplasty (PTCA), patients may have ischemia after the procedure because of the overall coronary disease and luminal renarrowing at the lesion sites. The aim of this study was to examine the effects of the calcium-channel blocker amlodipine on post-PTCA ischemia.

METHODS

In a prospective, double-blind design, patients were randomized to receive 10 mg of amlodipine or placebo 2 weeks before angioplasty. Exercise tests and 48-hour ambulatory electrocardiography recordings were performed in 405 patients, 2 weeks before and 2 and 20 weeks (early and late) after PTCA.

RESULTS

There were no differences in clinical and angiographic baseline characteristics between the treatment groups. Ischemia and angina were equally distributed before PTCA, and no difference in restenosis was found between the groups at follow-up. The incidence of angina was significantly lower in the amlodipine group compared with the placebo group both early and late after PTCA (P =.04 and.03). Exercise-induced ischemia was reduced by 40% (P =.009) early and 34% (P =.02) late after PTCA in the amlodipine group, and ischemia on ambulatory electrocardiography was reduced by 18% early and 28% late after PTCA compared with placebo (P =.06 and P =.009).

CONCLUSION

Ischemia and angina occurred after successful PTCA and were significantly reduced by amlodipine.

Cardiovascular prevention and blood pressure reduction: a quantitative overview updated until 1 March 2003

BACKGROUND

In a meta-analysis published in October 2001, we reported that new and old classes of antihypertensive drugs had similar long-term efficacy and safety. Furthermore, we observed that in clinical trials in hypertensive or high-risk patients gradients in systolic pressure accounted for most differences in outcome.

OBJECTIVE

To test whether our previous conclusions would hold, we updated our quantitative overview with new information from 14 clinical trials presented before 1 March 2003.

METHODS

To compare new and old antihypertensive drugs, we computed pooled odds ratios from stratified 2 x 2 contingency tables. If Zelen's test of heterogeneity was significant, we used a random effects model. In a meta-regression analysis, we correlated odds ratios with corresponding between-group differences in systolic pressure. We then contrasted observed odds ratios with those predicted from gradients in systolic pressure.

MAIN OUTCOMES

Differences in achieved systolic blood pressure and incidence of total and cardiovascular mortality, cardiovascular events, stroke, myocardial infarction and heart failure. NEW VERSUS OLD DRUGS: In 15 trials, 120 574 hypertensive patients were randomized to old drugs (diuretics or beta-blockers) or new agents [calcium-channel blockers, alpha-blockers, angiotensin-converting enzyme (ACE) inhibitors or angiotensin type-1 receptor (AR1) blockers]. Old and new drugs provided similar protection against total and cardiovascular mortality and fatal plus non-fatal myocardial infarction. Calcium-channel blockers, including (-8%, P = 0.07) or excluding verapamil (-10%, P = 0.02), as well as AR1 blockers (-24%, P = 0.0002) resulted in better stroke prevention than did the old drugs, whereas the opposite trend was observed for ACE inhibitors (+10%, P = 0.03). The risk of heart failure was higher (P < 0.0001) on calcium-channel blockers (+33%) and alpha-blockers (+102%) than on conventional therapy involving diuretics. META-REGRESSION: Between-group differences in achieved systolic pressure ranged from 0.1 to 3.2 mmHg in seven actively controlled trials (73 237 patients), and from 2.1 to 22.1 mmHg in seven studies comparing varying intensities of blood pressure lowering (11 128 patients). For these 14 new trials, we predicted outcome from achieved systolic blood pressure using our previously published meta-regression models based on 30 trials with 149 407 patients. In general, predicted and observed odds ratios were similar. Larger reductions in systolic pressure (weighted mean 1.8 mmHg) in two trials accounted for the advantage of AR1 blockers over conventional therapy in the prevention of stroke. Only for cardiovascular mortality in very old patients (P = 0.02) and for cardiovascular events and myocardial infarction in old Australians (P < 0.05), the observed odds ratios deviated from our predictions based on the gradients in systolic blood pressure.

INTERPRETATION

The hypothesis that new antihypertensive drugs, such as calcium-channel blockers, alpha-blockers, ACE inhibitors or AR1 blockers might influence cardiovascular prognosis over and beyond their antihypertensive effects remains unproven. The finding that blood pressure differences largely accounted for cardiovascular outcome emphasizes the desirability of tight blood pressure control. However, the level to which blood pressure must be lowered to achieve maximal benefit remains currently unknown.

Percutaneous coronary intervention vs. medical therapy: what are the implications for women?

There have been eight major studies assessing percutaneous coronary intervention (PCI) vs. medical therapy in the past 10 years. Women were inadequately represented in many of these studies, but because of similar long-term survival curves in women and men, most of the PCI data can be applied to women until more trials are published. According to currently available data, PCI offers greater angina relief and improvement in exercise tolerance than medicine alone, but has a greater risk of procedure-related complications in women. As a result of the rapid advancement of cardiovascular therapy, many of these studies did not incorporate optimal medical therapy or current PCI therapies. It is likely that for most patients (including women) with moderate angina, the best management may be a combination of PCI, medical therapy, and lifestyle changes.

Mechanisms of angioplasty and stent restenosis: implications for design of rational therapy

Restenosis after angioplasty or stenting remains the major limitation of both procedures. A vast array of drug therapies has been used to prevent restenosis, but they have proven to be predominantly unsuccessful. Recent trends in drug therapy have attempted to refine the molecular and biological targets of therapy, based on the assumption that a single biological process or molecule is critical to restenosis. In contrast, both stenting and brachytherapy, which are highly nonspecific, can successfully reduce restenosis after angioplasty or stenting, respectively. This review examines the biology of both angioplasty and stent stenosis, focussing on human studies. We also review the landmark human trials that have definitively proven successful therapies, such as stenting and brachytherapy. We suggest that the successful trials of stenting and brachytherapy and the failure of other treatments have highlighted the shortcomings of conventional animal models of arterial intervention, and gaps in our knowledge of human disease. In contrast to arguments advocating gene therapy, these studies suggest that the most likely successful drug therapy will have a wide therapeutic range, targeting as many of the components or biological processes contributing to restenosis as possible.