No-reflow phenomenon in stroke patients: A systematic literature review and meta-analysis of clinical data

BACKGROUND

The no-reflow phenomenon refers to the absence of microvascular reperfusion despite macrovascular reperfusion.

AIM

The aim of this analysis was to summarize the available clinical evidence on no-reflow in patients with acute ischemic stroke.

METHODS

A systematic literature review and a meta-analysis of clinical data on definition, rates, and impact of the no-reflow phenomenon after reperfusion therapy was carried out. A predefined research strategy was formulated according to the Population, Intervention, Comparison, and Outcome (PICO) model and was used to screen for articles in PubMed, MEDLINE, and Embase up to 8 September 2022. Whenever possible, quantitative data were summarized using a random-effects model.

RESULTS

Thirteen studies with a total of 719 patients were included in the final analysis. Most studies (n = 10/13) used variations of the Thrombolysis in Cerebral Infarction scale to evaluate macrovascular reperfusion, whereas microvascular reperfusion and no-reflow were mostly assessed on perfusion maps (n = 9/13). In one-third of stroke patients with successful macrovascular reperfusion (29%, 95% confidence interval (CI), 21-37%), the no-reflow phenomenon was observed. Pooled analysis showed that no-reflow was consistently associated with reduced rates of functional independence (odds ratio (OR), 0.21, 95% CI, 0.15-0.31).

CONCLUSION

The definition of no-reflow varied substantially across studies, but it appears to be a common phenomenon. Some of the no-reflow cases may simply represent remaining vessel occlusions, and it remains unclear whether no-reflow is an epiphenomenon of the infarcted parenchyma or causes infarction. Future studies should focus on standardizing the definition of no-reflow with more consistent definitions of successful macrovascular reperfusion and experimental set-ups that could detect the causality of the observed findings.

Tongmai Yangxin pill reduces myocardial No-reflow via endothelium-dependent NO-cGMP signaling by activation of the cAMP/PKA pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Tongmai Yangxin pill (TMYX) is derived from the Zhigancao decoction recorded in Shang han lun by Zhang Zhongjing during the Han dynasty. TMYX is used for the clinical treatment of chest pain, heartache, and qi-yin-deficiency coronary heart disease. Previous studies have confirmed that TMYX can improve vascular endothelial function in patients with coronary heart disease by upregulating nitric oxide activity and then regulating vascular tension. Whether TMYX can further improve myocardial NR by upregulating NO activity and then dilating blood vessels remains unclear.

AIM OF THE STUDY

This study aimed to reveal whether TMYX can further improve myocardial NR by upregulating NO activity and then dilating blood vessels. The underlying cAMP/PKA and NO-cGMP signaling pathway-dependent mechanism is also explored.

MATERIALS AND METHODS

The left anterior descending coronary arteries of healthy adult male SD rats were ligated to establish the NR model. TMYX (4.0 g/kg) was orally administered throughout the experiment. Cardiac function was measured through echocardiography. Thioflavin S, Evans Blue, and TTC staining were used to evaluate the NR and ischemic areas. Pathological changes in the myocardium were assessed by hematoxylin-eosin staining. An automated biochemical analyzer and kit were used to detect the activities of myocardial enzymes and myocardial oxidants, including CK, CK-MB, LDH, reactive oxygen species, superoxide dismutase, malonaldehyde, and NO. The expression levels of genes and proteins related to the cAMP/PKA and NO/cGMP signaling pathways were detected via real-time fluorescence quantitative PCR and Western blot analysis, respectively. A microvascular tension sensor was used to detect coronary artery diastolic function in vitro.

RESULTS

TMYX elevated the EF, FS, LVOT peak, LVPWd and LVPWs values, decreased the LVIDd, LVIDs, LV-mass, IVSd, and LV Vols values, demonstrating cardio-protective effects, and reduced the NR and ischemic areas. Pathological staining showed that TMYX could significantly reduce inflammatory cell number and interstitial edema. The activities of CK, LDH, and MDA were reduced, NO activity was increased, and oxidative stress was suppressed after treatment with TMYX. TMYX not only enhanced the expression of Gs-α, AC, PKA, and eNOS but also increased the expression of sGC and PKG. Furthermore, TMYX treatment significantly decreased ROCK expression. We further showed that TMYX (25-200 mg/mL) relaxed isolated coronary microvessels.

CONCLUSIONS

TMYX attenuates myocardial NR after ischemia and reperfusion by activating the cAMP/PKA and NO/cGMP signaling pathways, further upregulating NO activity and relaxing coronary microvessels.

The Spontaneous Coronary Slow-Flow Phenomenon: Reversal by Intracoronary Nicardipine

OBJECTIVE

An under-recognized cause of chest pain, the coronary slow-flow (CSF) phenomenon is characterized by delayed coronary opacification during diagnostic angiography in the absence of epicardial coronary artery disease (CAD). Given its angiographic resemblance to no-reflow during percutaneous coronary intervention, a condition associated with microvascular spasm responsive to calcium-channel blockers, we hypothesized that spontaneous CSF may similarly be reversed by intracoronary (IC) nicardipine.

METHODS

The effect of IC nicardipine was evaluated in 30 patients. CSF was defined as spontaneously delayed flow (<TIMI 3) during diagnostic coronary angiography in the absence of obstructive epicardial CAD or other conditions associated with impaired flow. Nicardipine was administered as a 200 μg IC bolus, after which repeat angiography was performed. Coronary flow before and after nicardipine was evaluated by TIMI flow grade and corrected TIMI frame count (TFC) assessments.

RESULTS

The study population consisted of 22 men and 8 women (mean age, 54 ± 11 years). Clinical presentation was rest angina in 21 patients (70%). At baseline, CSF with <TIMI 3 flow was observed in 49 vessels. TFC was prolonged (>27) in 68/90 vessels (76%). IC nicardipine produced markedly accelerated coronary filling, which was corroborated by TFC analysis. TFC was 47 ± 17 before vs 15 ± 5 after nicardipine (P<.001). All vessels demonstrated TIMI 3 flow and TFC <28 after nicardipine treatment.

CONCLUSIONS

IC nicardipine appears highly effective in reversing spontaneous CSF. These findings implicate microvascular spasm in the pathogenesis of CSF. Future studies of oral calcium-channel blockers in the long-term management of CSF are needed.

Adenosine and verapamil for no-reflow during primary percutaneous coronary intervention in people with acute myocardial infarction

BACKGROUND

Primary percutaneous coronary intervention (PPCI) is the preferred treatment for ST-segment elevation myocardial infarction. Although coronary flow is restored after PPCI, impaired myocardial perfusion (known as no-reflow) related to poor clinical outcomes is frequently observed. To overcome this phenomenon, drugs, such as atorvastatin, abciximab and others, have been tried as adjunctive treatment to PPCI. Among these drugs, verapamil and adenosine are among the most promising. No other systematic reviews have examined use of these two drugs in people with acute myocardial infarction (AMI) undergoing PPCI. This is an update of the version previously published (2013, Issue 6), for which the people of interest in the review were those treated with PPCI - not those given fibrinolytic therapy.

OBJECTIVES

To study the impact of adenosine and verapamil on no-reflow during PPCI in people with AMI.

SEARCH METHODS

We updated searches of the following databases in June 2014 without language restriction: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science and BIOSIS, China National Knowledge Infrastructure and clinical trials registers (ClinicalTrials.gov, Current Controlled Trials, Australian and New Zealand Clinical Trials Registry, the World Health Organization (WHO) International Clinical Trials Registry Platform). We also handsearched The American Journal of Cardiology.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) in which adenosine or verapamil was the primary intervention. Participants were individuals diagnosed with AMI who were undergoing PPCI.

DATA COLLECTION AND ANALYSIS

Two review authors collected studies and extracted data. When necessary, we contacted trial authors to obtain relevant information. We calculated risk ratios (RRs), P values and 95% confidence intervals (CIs) of dichotomous data.

MAIN RESULTS

We included in our review 11 RCTs (one new study with 59 participants) involving 1027 participants. Ten RCTs were associated with adenosine and one with verapamil. We considered the overall risk of bias of included studies to be moderate. We found no evidence that adenosine reduced short-term all-cause mortality (RR 0.61, 95% CI 0.25 to 1.48, P value = 0.27), long-term all-cause mortality (RR 0.78, 95% CI 0.22 to 2.74, P value = 0.70), short-term non-fatal myocardial infarction (RR 1.32, 95% 0.33 to 5.29, P value = 0.69) or myocardial blush grade (MBG) 0 to 1 after PPCI (RR 0.96, 95% CI 0.76 to 1.22, P value = 0.75). The incidence of thrombolysis in myocardial infarction (TIMI) flow grade < 3 after PPCI (RR 0.62, 95% CI 0.42 to 0.91, P value = 0.01) was decreased. Conversely, adverse events with adenosine, such as bradycardia (RR 6.32, 95% CI 2.98 to 13.41, P value < 0.00001), hypotension (RR 11.43, 95% CI 2.75 to 47.57, P value = 0.0008) and atrioventricular (AV) block (RR 6.78, 95% CI 2.15 to 21.38, P value = 0.001), were significantly increased.Meta-analysis of verapamil as treatment for no-reflow during PPCI was not performed because data were insufficient.

AUTHORS' CONCLUSIONS

It is difficult to draw conclusions because of the insufficient quality and quantity of current research studies. We considered the overall risk of bias of included studies to be moderate. Adenosine as treatment for no-reflow during PPCI could reduce angiographic no-reflow (TIMI flow grade < 3) but was found to increase adverse events. What's more, no evidence could be found to suggest that adenosine reduced all-cause mortality, non-fatal myocardial infarction or the incidence of myocardial blush grade 0 to 1. Additionally, the efficacy of verapamil for no-reflow during PPCI could not be analysed because data were insufficient. Further clinical research into adenosine and verapamil is needed because of the limited numbers of available trials and participants.

Nicorandil Versus Nitroglycerin for Symptomatic Relief of Angina in Patients With Slow Coronary Flow Phenomenon: A Randomized Clinical Trial

OBJECTIVE

Patients with the coronary slow flow phenomenon frequently experience angina episodes. The present study aimed to compare the efficacy of nicorandil versus nitroglycerin for alleviation of angina symptoms in slow flow patients.

METHODS

In a single-center, single-blind, parallel-design, comparator-controlled, randomized clinical trial (NCT02254252), 54 patients with slow flow and normal or near-normal coronary angiography who presented with frequent angina episodes were randomly assigned to 1-month treatment with nicorandil 10 mg, 2 times a day (n = 27) or sustained-release glyceryltrinitrate 6.4 mg 2 times a day (n =27). Frequency of angina episodes, pain intensity, and the Canadian Cardiovascular Society (CCS) grading of angina pectoris were assessed at baseline and after 1 month of treatment.

RESULTS

In all, 25 patients in the nicorandil arm and 24 patients in the nitroglycerin arm were analyzed. After 1 month, patients treated with nicorandil had fewer angina episodes (adjusted mean number of episodes per week, nicorandil versus nitroglycerin; 1.68 ± 0.15 vs 2.29 ± 0.15, P = .007, effect size = 14.6%). Patients also reported greater reductions in pain intensity with nicorandil versus nitroglycerin (adjusted mean of self-reported pain score; 3.03 ± 0.29 vs 3.89 ± 0.30, P = .046, effect size = 8.4%). A significantly higher proportion of patients in the nicorandil arm were categorized in CCS class I (76% vs 33.3%, P = .004) or class II (16.0% vs 45.8%, P = .032).

CONCLUSION

In slow flow patients, nicorandil provides better symptomatic relief of angina than nitroglycerin.

Effects of verapamil and adenosine in an adjunct to tirofiban on resolution and prognosis of noreflow phenomenon in patients with acute myocardial infarction

AIM

We aimed to investigate the effects of verapamil and adenosine in an adjunct to intravenous tirofiban on management and prognosis of no-reflow phenomenon during primary percutaneous coronary intervention (PPCI) and to compare their efficacies on reversing of no-reflow phenomenon and short and midterm survival.

METHODS

We included 46 patients with acute ST-segment elevation myocardial infarction (STEMI) and occurrence of no-reflow phenomenon after PPCI. All patients received intravenous tirofiban and then randomized into one of the following 3 groups: intracoronary adenosine (N.=16), intracoronary verapamil (N.=15) or placebo (N.=15).

RESULTS

Intracoronary verapamil therapy had significant effect in restoring impaired coronary blood flow by decreasing thrombolysis in myocardial infarction (TIMI) frame count from 73±44 to 52±48 (P=0.024). However, adenosine and serum physiologic administration were not found to be so effective in decreasing TIMI frame count (from 81±35 to 71±46, P=0.084; from 74±32 to 71±37, P=0.612, respectively). In-hospital and 6-month survival rates were similar among groups.

CONCLUSION

In conclusion, intracoronary verapamil restored the impaired coronary blood flow more effectively than adenosine or placebo. However, none of them has changed the clinical course in the first 6 months.

Adenosine and verapamil for no-reflow during primary percutaneous coronary intervention in people with acute myocardial infarction

BACKGROUND

Primary percutaneous coronary intervention (PPCI) is the preferred treatment for ST segment elevation myocardial infarction. Although there is restoration of coronary flow after PPCI, impaired myocardial perfusion (known as no-reflow) is frequently observed, and is related to poor clinical outcomes. In order to overcome this phenomenon, drugs have been tried as adjunctive treatments to PPCI. Among them, verapamil and adenosine are two of the most promising drugs. There are no systematic reviews of these two drugs in people with acute myocardial infarction (AMI) undergoing PPCI.

OBJECTIVES

To study the impact of adenosine and verapamil on people with AMI who are undergoing PPCI.

SEARCH METHODS

We searched the following databases in February 2012: the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE, EMBASE, Web of Science and BIOSIS, China National Knowledge Infrastructure, Clinical Trials registers (Clinical Trials.gov, Current Controlled Trials, Australian & New Zealand Clinical Trials Registry, the WHO International Clinical Trials Registry Platform). We also handsearched the American Journal of Cardiology.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) where adenosine or verapamil was the primary intervention. Participants were individuals diagnosed with AMI who were undergoing PPCI.

DATA COLLECTION AND ANALYSIS

Two review authors collected studies and extracted data. Where necessary, we contacted the trial authors to obtain the relevant information. We calculated risk ratios (RRs), P values, and 95% confidence intervals (CIs) of dichotomous data.

MAIN RESULTS

We included 10 RCTs involving 939 participants in our review. Nine RCTs were associated with adenosine and one with verapamil. We considered the overall risk of bias of included studies to be moderate. There was no evidence that adenosine reduced short-term all-cause mortality (RR 0.61, 95% CI 0.23 to 1.61, P = 0.32), long-term all-cause mortality (RR 1.20, 95% CI 0.27 to 5.22, P = 0.81), short-term non-fatal myocardial infarction (RR 1.38, 95% 0.28 to 6.96, P = 0.69) or the incidence of angiographic no-reflow (TIMI flow grade < 3 after PPCI: RR 0.72, 95% CI 0.49 to 1.07, P = 0.11, and myocardial blush grade (MBG) 0 to 1 after PPCI: RR 0.96, 95% CI 0.76 to 1.22, P=0.75). But the incidence of adverse events with adenosine, such as bradycardia (RR 6.57, 95% CI 2.94 to 14.67, P<0.00001), hypotension (RR 11.43, 95% CI 2.75 to 47.57, P=0.0008) and atrioventricular (AV) block (RR 6.67, 95% CI 1.52 to 29.21, P=0.01) was significantly increased.Meta-analysis of verapamil as treatment for no-reflow during PPCI was not calculated due to lack of data.

AUTHORS' CONCLUSIONS

We found no evidence that adenosine and verapamil as treatments for no-reflow during PPCI can reduce all-cause mortality, non-fatal myocardial infarction or the incidence of angiographic no-reflow (TIMI flow grade < 3 and MBG 0 to1), but there was some evidence of increased adverse events. Further clinical research into adenosine and verapamil is needed because of the limited numbers of included trials and participants.

Intracoronary injection of drugs to treat no--reflow phenomenon and microcirculatory dysfunction

In a variant proportion of patients presenting with chest pain and electrocardiographic changes characteristic for ST - elevation myocardial infarction, percutaneous coronary intervention achieves epicardial coronary artery reperfusion but not the myocardial reperfusion (ranging from 5% to 50%). Furthermore, prolonged myocardial ischemia often breaks down the coronary microvasculature and the flow to the infarct myocardium may seem to be markedly reduced. This condition is known as no reflow - phenomenon. The no reflow - phenomenon is associated with an increased incidence of malignant ventricular arrhythmias, heart failure and 30-days mortality. In the recent years in literature, several articles (subsequently discussed in the present review) have been published and made relevant to the study of the pathophysiology regarding no reflow - phenomenon. This knowledge has assisted in the development of new treatment strategies, such as prophylactic use of vasodilators, mechanical devices and drugs inhibiting platelet. The review has focused on the current literature about intra - coronary injection of drugs to treat no - reflow and microvascular dysfunction.

Effects of L-NAME on coronary blood flow, infarct size and the extent of the no-reflow phenomenon

BACKGROUND

NOS inhibitors are a potential treatment for patients with cardiogenic shock during acute myocardial infarction. Despite hemodynamic efficacy, their effects on the extent of myocardial infarction (MI) and the no-reflow phenomenon (NRP) have not been clarified.

METHODS

Sixteen pigs underwent occlusion of the mid left anterior descending coronary artery for 1h followed by reperfusion for 2h. Coronary blood flow (CBF), distal to the occlusion site, was measured. In eight experiments, L-NAME (non selective NO synthetase inhibitor) administration began 10 min before the onset of reperfusion and continued for 2h (loading dose 1mg/kg, perfusion rate: 1mg/kg/h) (L-NAME group). Eight pigs received similarly normal saline (controls). At the end of each experiment, the myocardial area at risk (MAR) and extent of MI and NRP were measured.

RESULTS

Hemodynamics at baseline and during ischemia were similar in both groups. During reperfusion, the mean aortic blood pressure was significantly higher in the l-NAME group. In both groups, CBF reached a peak at 5 min of reperfusion, (no difference between groups). CBF gradually returned to baseline levels within 60 min of reperfusion in both groups. No statistically significant differences in the extent of the NRP (51.8 ± 19.7 vs 60.9 ± 11.4 p=0.35) and MI (77.9 ± 13.9 vs 77.1 ± 8.8 p=0.92), both expressed as a percentage of MAR, were observed between the L-NAME group and the control group.

CONCLUSIONS

L-NAME administration started immediately before and maintained throughout reperfusion has no effect on NRP and MI size. L-NAME might stabilize patients with post-MI cardiogenic shock without adverse effects on infarct size.

A randomized, single-center double-blinded trial on the effects of diltiazem sustained-release capsules in patients with coronary slow flow phenomenon at 6-month follow-up

Objective

The aim of this study is to observe the chronic effects of diltiazem release capsules on patients with coronary slow flow (CSF) phenomenon.

Methods

From 2004 to 2009, 80 consecutive patients with chest pain and normal coronary arteries evidenced by coronary angiography and CSF were included in this randomized, double-blind, placebo-controlled trial. CSF patterns were evaluated by the corrected TIMI frame count. Patients were randomly assigned at 1∶1 ratio to diltiazem sustained-release capsules treatment group (Dil, 90 mg twice daily) or placebo control group. Holter, liver and kidney function, treadmill exercise test, coronary angiography and left ventricular angiography were measured at baseline and after 6 months. The incidence of cardiovascular events (re-admission or progress in coronary heart disease, myocardial infarction, malignant arrhythmia or cardiac death) was evaluated during the 6 months follow up.

Results

Thirty-nine patients in control and 40 patients in Dil group completed the 6 months follow-up. There was no medication induced drug withdraw during follow up. Left ventricular ejection fraction was similar between the 2 groups at baseline and during follow up. Heart rate was significantly lower in Dil group than in control group and there was no symptomatic bradycardia and II and III degree atrioventricular conduction block in both groups. Significant improvement was observed in the onset of chest pain, treadmill exercise test and coronary blood flow in Dil group while these parameters remained unchanged in control group at the end of 6 months follow up. The incidence of cardiovascular events was similar between the two groups.

Conclusion

Diltiazem slow-release capsules improved coronary blood flow and alleviated angina in patients with CSF.

Trial Registration

Chinese Clinical Trial Registry ChiCTR-TCC-11001864

Coronary slow flow and acute coronary syndrome in a patient with spinal cord injury

We report the case of a 55-year-old man who presented with acute coronary syndrome due to coronary slow flow after spinal cord injury. Data regarding the causes and clinical manifestations of coronary slow flow are inconclusive, but the autonomic nervous system is believed to be at least a contributing factor. The predominant vagal activity causes vasodilation and hemostasis, which can lead to acute coronary syndrome. We hereby call attention to hyperactive parasympathetic tonicity, which can lead to coronary slow flow and acute coronary syndrome in acute spinal cord injury patients.

Beneficial effects of nebivolol treatment on oxidative stress parameters in patients with slow coronary flow

OBJECTIVES

Imbalance between oxidative stress and antioxidant defense has been demonstrated in patients with slow coronary flow (SCF). The aim of this study was to investigate the effect of nebivolol treatment on oxidative stress parameters in SCF patients.

STUDY DESIGN

The study included 32 patients (10 females, 22 males; mean age 53.3 ± 5.2 years) with SCF and 32 control subjects (14 females, 18 males; mean age 50.6 ± 5.2 years) with normal coronary arteries on angiography. Coronary slow flow was determined by the TIMI frame count method. Patients with SCF received nebivolol treatment (5 mg/day) for six months. Blood samples were analyzed for malondialdehyde (MDA) and serum nitric oxide (NO) levels, and erythrocyte catalase (CAT) and erythrocyte superoxide dismutase (SOD) activities in the control group and, in SCF patients, at baseline and after six months of nebivolol treatment.

RESULTS

The two groups were similar with respect to age, body mass index, blood pressure, heart rate, and lipid profile. Smoking was more frequent in the SCF group compared to the controls. TIMI frame counts measured from the left anterior descending, circumflex, and right coronary arteries were significantly higher in the SCF group (p < 0.0001). Baseline MDA and NO levels, and SOD and CAT activities were significantly different between the two groups, with significantly increased MDA (p < 0.0001), and significantly decreased SOD (p < 0.0001), CAT (p < 0.001), and NO (p < 0.001) in the SCF group. After six months of nebivolol treatment, all oxidative stress parameters showed significant improvements compared to the baseline values (p < 0.0001 for MDA, SOD, CAT, and NO) and approximated to the values of the control group.

CONCLUSION

Our results show that nebivolol treatment may be beneficial to improve oxidative stress parameters in patients with SCF, which are considered to be an early stage of atherosclerosis.

[Effects of intracoronary administration of nitroglycerin and verapamil for treatment of coronary slow flow phenomenon]

OBJECTIVE

To assess the efficacy of intracoronary nitroglycerin and verapamil for patients with the coronary slow flow phenomenon (CSFP).

METHODS

Sixty-four patients with CSFP without stenotic lesions during diagnostic coronary angiography were enrolled and divided into the nitroglycerin group (n = 35) and verapamil group (n = 29), 29 patients with normal coronary flow served as normal control. CSFP was defined when 4 or more heart beats were needed for contrast media to opacify the distal vasculature. Intracoronary injection of 100 - 400 microg nitroglycerin or verapamil through the diagnostic catheter was applied to patients with CSFP to improve coronary flow. The coronary blood flow was evaluated by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method.

RESULTS

Clinical characteristics were similar among the three groups. The basic TFCs of left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA) were 78.3 +/- 19.4, 57.2 +/- 14.6, 56.9 +/- 12.5 in the verapamil group, and were 70.8 +/- 21.7, 55.3 +/- 12.5, 51.1 +/- 15.4 in the nitroglycerin group, respectively, which were significantly higher than those in the normal controls (LAD 29.2 +/- 4.4, LCX 23.1 +/- 3.5 and RCA 19.7 +/- 1.8, respectively). After the administration of drugs, the TFCs of LAD, LCX and RCA were 42.3 +/- 8.9, 36.7 +/- 6.8, 30.3 +/- 5.9 respectively (all P < 0.01 vs. baseline) in the nitroglycerin group and 37.7 +/- 9.3, 31.5 +/- 11.3, 24.6 +/- 4.4 respectively (all P < 0.01 vs. baseline) in the verapamil group. The TFCs after drug administration in both therapy groups were significantly higher than that in normal controls (all P < 0.05). The TFCs decrease in the verapamil group were more significant than that in the nitroglycerin group (all P < 0.05).

CONCLUSION

Intracoronary administration of verapamil could result in more coronary flow improvement in patients with CSFP than nitroglycerin, although the post therapy coronary flow was still slower than normal.

[Increasing efficacy of recanalization of infarction-associated coronary artery by means of pharmacological agent imitating pre- and postconditioning phenomenon (review of literature)]

Analyzing the literature data shows that the formation of the necrosis focus in patients presenting with acute myocardial infarction (AMI) is mainly completed within 2-4 hours from the moment of the development of coronary thrombosis. A positive effect of throm bolytic therapy and coronary angioplasty observed at later terms is apparently associated with restoration ofcoronaryperfusion in the periinfarction zone. The protecting effect of adenosine in acute myocardial infarction (AMI) does not probably depend upon the size of the infarction focus but is due to decreased incidence of the development of the no-reflow phenomenon. The protective effect on nicotinamide seen in patients with AMI is probably associated with improved coronary perfusion in the periinfarction zone. Opioids and cannabioids imitate the pre- and postconditioning phenomenon. Hence, these compounds after cl employed in comprehensive therapy ofAMI.

The no-reflow phenomenon in the coronary circulation

The no-reflow phenomenon is a poorly understood complication of percutaneous coronary intervention in which diminished blood flow to distal microvascular beds persists despite the successful treatment of the occlusive lesion from the epicardial coronary artery or arteries. In this contemporary review we endeavour to discuss the pathophysiology of coronary no-reflow, understand the predictors and describe current pharmacological and mechanical strategies to prevent and treat coronary no-reflow.

[Effect of urapidil on heart function and ventricular systolic synchrony in acute myocardial infarction patients with no-reflow phenomenon after percutaneous coronary intervention]

OBJECTIVE

To evaluate the influence of intracoronary administration of urapidil on myocardial blush grade (MBG) and left ventricular systolic function and synchrony in the acute myocardial infarction (AMI) patients with no-reflow phenomenon after percutaneous coronary intervention (PCI) identified by MBG.

METHODS

Forty-three patients with AMI, in whom primary PCI was successfully performed (6.25+/-2.37) hours after the onset of angina pectoris,were found to have no-reflow phenomenon. They were randomized into two groups: urapidil group (n=22) and no-reflow control group (n=21). Nitroglycerin (200 microg) was injected into coronary artery. Urapidil (5 mg) was injected into coronary artery after 10 minutes in the urapidil group, and 0.9% NaCl (5 ml, weight percentage) was injected into coronary artery in the no-reflow control group. All the patients received same standard therapy afterwards. The left ventriculography (LVG) was performed immediately and 6 months after PCI to measure the ventricular volume, left ventricular end-diastolic pressure (LVEDP), and wall motion score (WMS). Equilibrium radionuclide angiography (ERNA) was performed 1 week and 6 months after PCI to determine the parameters of left ventricular systolic function and systolic synchrony.

RESULTS

The MBG of urapidil group and control group was grade 0.77+/-0.31 and grade 0.77+/-0.28 after PCI, respectively. The MBG remained unchanged in control group and significantly increased from grade 0.77+/-0.31 to grade 2.37+/-0.27 10 minutes in urapidil group (P<0.05). Follow-up at 6 months after AMI-PCI, left ventricular end-systolic volume index (LVESVI), left ventricular end-diastolic volume index (LVEDVI), WMS and LVEDP were significantly lower in urapidil group compared with those in control group respectively (all P<0.05). The values of left ventricular ejection fraction (LVEF), peak ejection rate (PER), peak filling rate (PFR) of the ERNA as measured by ERNA were significantly increased in urapidil group compared with that in control group (all P<0.05). Phase analysis showed that the left ventricular systolic synchrony parameters phase shift (PS), full width at half maximum (FWHM) and peak phase standard deviation (PSD) were also significantly lower in urapidil group than those in control group (all P<0.05).

CONCLUSION

Intracoronary administration of urapidil can attenuate the no-reflow phenomenon, improve the left ventricular systolic function and synchrony in patients with no-reflow phenomenon after AMI-PCI.

[Effects of intracoronary diltiazem on no-reflow phenomenon after emergent percutaneous coronary intervention in patients with acute myocardial infarction]

OBJECTIVE

To assess the effects of intracoronary diltiazem on no-reflow phenomenon of infarct-related artery (IRA) after emergent percutaneous transluminal coronary angioplasty or/and intracoronary stenting (PTCA/Stenting) in the patients with acute myocardial infarction (AMI).

METHODS

We studied 34 AMI patients with no-reflow phenomenon of IRA after emergent PTCA/Stenting between January 1999 and August 2005. Urokinase-treated group (n=16) was given intracoronary urokinase 30,0000 - 50,0000 units within 15 - 30 minutes between January 1999 and April 2002 while diltiazem-treated group (n=18) was given intracoronary diltiazem 0.5 - 2 mg within 10 - 30 minutes between May 2002 and August 2005. Fifteen minutes later, coronary arteriography (CAG) was performed and the thrombolysis in myocardial infarction (TIMI) flow grade was measured.

RESULTS

No apparent change of TIMI flow grade was found between pre-administration and post-administration of intracoronary urokinase, but TIMI flow grade was significantly improved after intracoronary diltiazem (P<0.01). TIMI flow grade of diltiazem-treated group was significantly higher than that of urokinase-treated group after the administration (P<0.05). The percentage of the patients who reached TIMI flow grade 3 after the intracoronary administration was higher in the diltiazem-treated group than that in the urokinase-treated group (P<0.01).

CONCLUSION

The intracoronary administration of diltiazem 0.5~2mg can effectively improve the no-reflow phenomenon after emergent PTCA/Stenting in patients with AMI.