Comparison of combination therapy of adenosine and nitroprusside with adenosine alone in the treatment of angiographic no-reflow phenomenon

Advances in nanotechnology-assisted photodynamic therapy for neurological disorders: a comprehensive review

Neurological disorders such as neurodegenerative diseases and nervous system tumours affect more than one billion people throughout the globe. The physiological sensitivity of the nervous tissue limits the application of invasive therapies and leads to poor treatment and prognosis. One promising solution that has generated attention is Photodynamic therapy (PDT), which can potentially revolutionise the treatment landscape for neurological disorders. PDT attracted substantial recognition for anticancer efficacy and drug conjugation for targeted drug delivery. This review thoroughly explained the basic principles of PDT, scientific interventions and advances in PDT, and their complicated mechanism in treating brain-related pathologies. Furthermore, the merits and demerits of PDT in the context of neurological disorders offer a well-rounded perspective on its feasibility and challenges. In conclusion, this review encapsulates the significant potential of PDT in transforming the treatment landscape for neurological disorders, emphasising its role as a non-invasive, targeted therapeutic approach with multifaceted applications.

No-Reflow Prediction in Acute Coronary Syndrome During Percutaneous Coronary Intervention: The NORPACS Risk Score

BACKGROUND

Suboptimal coronary reperfusion (no reflow) is common in acute coronary syndrome percutaneous coronary intervention (PCI) and is associated with poor outcomes. We aimed to develop and externally validate a clinical risk score for angiographic no reflow for use following angiography and before PCI.

METHODS

We developed and externally validated a logistic regression model for prediction of no reflow among adult patients undergoing PCI for acute coronary syndrome using data from the Melbourne Interventional Group PCI registry (2005-2020; development cohort) and the British Cardiovascular Interventional Society PCI registry (2006-2020; external validation cohort).

RESULTS

A total of 30 561 patients (mean age, 64.1 years; 24% women) were included in the Melbourne Interventional Group development cohort and 440 256 patients (mean age, 64.9 years; 27% women) in the British Cardiovascular Interventional Society external validation cohort. The primary outcome (no reflow) occurred in 4.1% (1249 patients) and 9.4% (41 222 patients) of the development and validation cohorts, respectively. From 33 candidate predictor variables, 6 final variables were selected by an adaptive least absolute shrinkage and selection operator regression model for inclusion (cardiogenic shock, ST-segment-elevation myocardial infarction with symptom onset >195 minutes pre-PCI, estimated stent length ≥20 mm, vessel diameter <2.5 mm, pre-PCI Thrombolysis in Myocardial Infarction flow <3, and lesion location). Model discrimination was very good (development C statistic, 0.808; validation C statistic, 0.741) with excellent calibration. Patients with a score of ≥8 points had a 22% and 27% risk of no reflow in the development and validation cohorts, respectively.

CONCLUSIONS

The no-reflow prediction in acute coronary syndrome risk score is a simple count-based scoring system based on 6 parameters available before PCI to predict the risk of no reflow. This score could be useful in guiding preventative treatment and future trials.

Efficacy of Shexiang Tongxin Dropping Pills in a Swine Model of Coronary Slow Flow

Objective: Preliminary clinical studies have confirmed that Shexiang Tongxin dropping pills (STDPs) could improve angina pectoris and attenuate vascular endothelial dysfunction in patients with slow coronary flow, but the underlying mechanism is not fully unclear. We aimed to investigate the impact of STDP in a swine model of coronary slow flow (SF) and related mechanisms.

Methods: SF was induced by coronary injection of 40μm microspheres, and pigs were randomly divided into the SF group and SF plus STDP group. Pigs in the STDP group received sublingual STDP for 10 min, followed by 1 g STDP oral administration daily for 6 days. Coronary angiography was performed, the TIMI frame count (TFC) was determined, and hemodynamic measurements were performed before, at 30 min, and 7 days post-SF. Serum levels of total NO, NOS, ET-1, C-TNI, and BNP were measured. Myocardial expressions of TNF and IL-6, eNOS, VEGF, CD31, and α-SMA were analyzed by immunohistochemistry and Western blotting.

Results: Compared to the SF group, LVEF and TFC were significantly improved at 7 days post-SF in the STDP group. The serum ET-1 level was significantly reduced at 7 days, and NO and NOS levels were significantly higher in the STDP group. Seven days post-SF, myocardial TNF and IL-6 expressions were significantly downregulated, while the expressions of eNOS and VEGF, CD31, and ɑ-SMA were significantly upregulated in the STDP group.

Conclusion: Our results showed that STDP improved cardiac function and coronary flow, possibly through reducing inflammatory responses and upregulating myocardial eNOS and VEGF, CD31, and the ɑ-SMA expression.

A Novel Biological Strategy for Myocardial Protection by Intracoronary Delivery of Mitochondria: Safety and Efficacy

Mitochondrial dysfunction is the determinant insult of ischemia-reperfusion injury. Autologous mitochondrial transplantation involves supplying one's healthy mitochondria to the ischemic region harboring damaged mitochondria. The authors used in vivo swine to show that mitochondrial transplantation in the heart by intracoronary delivery is safe, with specific distribution to the heart, and results in significant increase in coronary blood flow, which requires intact mitochondrial viability, adenosine triphosphate production, and, in part, the activation of vascular K_IR channels. Intracoronary mitochondrial delivery after temporary regional ischemia significantly improved myocardial function, perfusion, and infarct size. The authors concluded that intracoronary delivery of mitochondria is safe and efficacious therapy for myocardial ischemia-reperfusion injury.

Short-term effect of verapamil on coronary no-reflow associated with percutaneous coronary intervention in patients with acute coronary syndrome: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the clinical efficacy and safety of intracoronary verapamil injection in the prevention and treatment of coronary no-reflow after percutaneous coronary intervention (PCI).

HYPOTHESIS

Intracoronary verapamil injection may be beneficial in preventing no-reflow/slow-flow after PCI.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials database. Randomized trials comparing the efficacy and safety of intracoronary verapamil infusion vs control in patients with acute coronary syndrome (ACS) were included. Meta-analysis was performed by RevMan 5.0 software (Cochrane Collaboration, Copenhagen, Denmark) .

RESULTS

Seven trials involving 539 patients were included in the analysis. Verapamil treatment was significantly more effective in decreasing the incidence of no-reflow (risk ratio [RR]: 0.33; 95% confidence interval [CI]: 0.23 to 0.50) as well as reducing the corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) (weighted mean difference: -11.62; 95% CI: -16.04 to -7.21) and improving the TIMI myocardial perfusion grade (TMPG) (RR: 0.43; 95% CI: 0.29 to 0.64). Verapamil also reduced the 30-day wall motion index (WMI) compared to the control. Moreover, the procedure reduced the incidence of major adverse cardiac events (MACEs) in ACS patients during hospitalization (RR: 0.37; 95% CI: 0.17 to 0.80) and 2 months after PCI (RR: 0.56; 95% CI: 0.33 to 0.95). However, administration of verapamil did not provide an additional improvement of left ventricular ejection fraction regardless of the time that had passed post-PCI.

CONCLUSIONS

Intracoronary verapamil injection is beneficial in preventing no-reflow/slow-flow, reducing CTFC, improving TMPG, and lowering WMI. It is also likely to reduce the 2-month MACEs in ACS patients post-PCI.

Intracoronary fixed dose of nitroprusside via thrombus aspiration catheter for the prevention of the no-reflow phenomenon following primary percutaneous coronary intervention in acute myocardial infarction

Previous studies have shown that intracoronary (IC) nitroprusside (NTP) injection is a safe and effective strategy for the treatment of no-reflow (NR) during percutaneous coronary intervention (PCI). The present study tested the hypothesis that, on the basis of thrombus aspiration for the treatment of ST-segment elevation myocardial infarction (STEMI), the selective IC administration of a fixed dose of NTP (100 μg) plus tirofiban is a safe and superior treatment method compared with the IC administration of tirofiban alone for the prevention of NR during primary PCI. A total of 162 consecutive patients with STEMI, who underwent primary PCI within 12 h of onset, were randomly assigned to two groups: Group A, IC administration of a fixed dose of NTP (100 μg) plus tirofiban (10 μg/kg) and group B, IC administration of tirofiban (10 μg/kg) alone (n=80 and n=82, respectively). The drugs were selectively injected into the infarct-related artery (IRA) via a thrombus aspiration catheter advanced into the IRA. The primary end-point was post-procedural corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC). The proportion of complete (>70%) ST-segment resolution (STR); the TIMI myocardial perfusion grade (TMPG) 2–3 ratio following PCI; the peak value of creatine kinase (CK)-MB; the TIMI flow grade; the incidence of major adverse cardiac events (MACEs) and the left ventricular ejection fraction (LVEF) after 6 months of follow-up were observed as the secondary end-points. There were no significant differences in the baseline clinical and angiographic characteristics between the two groups. Compared with group B, group A had i) a lower CTFC (23±7 versus 29±11, P=0.000); ii) a higher proportion of complete STR (72.5 versus 55.9%, P=0.040); iii) an enhanced TMPG 2–3 ratio (71.3 versus 53.7%, P=0.030) and iv) a lower peak CK-MB value (170±56 versus 210±48 U/l, P=0.010). There were no statistically significant differences in the final TIMI grade-3 flow between the two groups (92.5 versus 91.5% for groups A and B, respectively; P=0.956). The LVEF at 6 months was higher in group A than group B (63±9 versus 53±11%, respectively; P=0.001); however, the incidence of MACEs was not statistically different between the two groups, although there was a trend indicating improvement in group A (log rank χ²=0.953, P=0.489). The selective IC administration of a fixed dose of NTP (100 μg) plus tirofiban via a thrombus aspiration catheter advanced into the IRA is a safe and superior treatment method compared with tirofiban alone in patients with STEMI undergoing primary PCI. This novel therapeutic strategy improves the myocardial level perfusion, in addition to reducing the infarct size. Furthermore, it may improve the postoperative clinical prognosis following PCI.

Treating and preventing no reflow in the cardiac catheterization laboratory

The no reflow phenomenon can happen during elective or primary percutaneous coronary intervention. This phenomenon is thought to be a complex process involving multiple factors that eventually lead to microvascular obstruction and endothelial disruption. Key pathogenic components include distal atherothrombotic embolization, ischemic injury, reperfusion injury, and susceptibility of coronary microcirculation to injury. Thus, pharmacologic and mechanical strategies to prevent and treat no reflow target these mechanisms. Specifically, pharmacologic therapy consisting of vasodilators and antiplatelet agents have shown benefit in the treatment of no-reflow and mechanical therapies such as distal protection and aspiration thrombectomy have also shown benefit.

Pharmacotherapy During Saphenous Vein Graft Intervention

Coronary revascularization using saphenous vein grafts is an important treatment modality for patients with severe coronary artery disease. Percutaneous intervention of these grafts is often the best option for patients who develop severe stenosis of the vein grafts. Use of adjunctive glycoprotein IIb/IIIa inhibitors does not confer added benefit with ischemic endpoints as compared with heparin alone, but it increases the risk of bleeding. Bivalirudin used as the primary anticoagulant lowers the risk of bleeding. No-reflow frequently complicates vein graft interventions but can be treated with vasoactive agents such as calcium channel blockers, adenosine, and nitroprusside.

REstoration of COronary flow in patients with no-reflow after primary coronary interVEntion of acute myocaRdial infarction (RECOVER)

BACKGROUND

No randomized trial has been conducted to compare different vasodilators for treating no-reflow during primary percutaneous coronary intervention (PCI) for ST-segment elevation acute myocardial infarction.

METHODS

The prospective, randomized, 2-center trial was designed to compare the effect of 3 different vasodilators on coronary no-reflow. A total of 102 patients with no-reflow in primary PCI were randomized to receive intracoronary infusion of diltiazem, verapamil, or nitroglycerin (n = 34 in each group) through selective microcatheter. The primary end point was coronary flow improvement in corrected thrombolysis in myocardial infarction frame count (CTFC) after administration of the drug.

RESULTS

Compared with that of the nitroglycerin group, there was a significant improvement of CTFC after drug infusion in the diltiazem and verapamil groups (42.4 frames vs 28.1 and 28.4 frames, P < .001). The improvement in CTFC was similar between the diltiazem and verapamil groups (P = .9). Compared with the nitroglycerin group, the diltiazem and verapamil groups had more complete ST-segment resolution at 3 hours after PCI, lower peak troponin T level, and lower N-terminal pro-B-type natriuretic peptide levels at 1 and 30 days after PCI. After drug infusion, the drop of heart rate and systolic blood pressure in the verapamil group was greater than that in the diltiazem and nitroglycerin groups.

CONCLUSION

Intracoronary infusion of diltiazem or verapamil can reverse no-reflow more effectively than nitroglycerin during primary PCI for acute myocardial infarction. The efficacy of diltiazem and verapamil is similar, and diltiazem seems safer.

Safety and efficacy of intracoronary adenosine administration in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention: a meta-analysis of randomized controlled trials

Background: Studies evaluating intracoronary administration of adenosine for prevention of microvascular dysfunction and ischemic-reperfusion injury in patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI) have yielded mixed results. Therefore, we performed a meta-analysis of these trials to evaluate the safety and efficacy of intracoronary adenosine administration in patients with AMI undergoing primary PCI.

Methods: A total of seven prospective randomized controlled trials were analyzed. The endpoints extracted were post-procedure residual stent thrombosis (ST) segment elevation and ST segment resolutions (STRes), difference in peak creatine kinase (CK-MB) concentration, thrombolysis in myocardial infarction (TIMI) grade III flow (TIMI 3 flow), myocardial blush grade (MBG) 3, mean difference in post-PCI ejection fraction (EF), all-cause mortality, cardiovascular mortality, heart failure (HF) and major adverse cardiovascular event (MACE). Safety endpoints analyzed were bradycardia, second-degree atrioventricular block (AVB), ventricular tachycardia (VT), ventricular fibrillation (VF) and recurrence of chest pain (CP). The endpoints were analyzed by standard methods of meta-analysis.

Results: Intracoronary adenosine therapy led to significantly more post-PCI STRes [relative risk (RR) 1.39, 95% confidence interval (CI) 1.01–1.90; p = 0.04] and reduction in residual ST segment elevation (RR 0.82, CI 0.69–0.99; p = 0.04) but did not improve TIMI 3 flow (RR 1.09, CI 0.94–1.27; p = 0.25), MBG3 (RR 1.04, CI 0.65–1.69; p = 0.88), peak CK-MB concentration (mean difference −39.43, CI −120.223 to 41.371; p = 0.339) and post-PCI EF (mean difference 1.238, CI −5.802 to 8.277; p = 0.730). There was a trend towards improvement and MACE (RR 0.64, CI 0.40–1.03; p = 0.06), incidence of HF (RR 0.47, CI 0.19–1.12; p = 0.08) and CV mortality (RR 0.15, CI 0.02–1.23; p = 0.08) that did not reach statistical significance but no difference in all-cause mortality (RR 0.77, CI 0.25–2.34; p = 0.64). Safety analysis showed no significant difference in CP events (RR 1.26, CI 0.55–2.86; p = 0.58), bradycardia (RR 2.19, CI 0.24–0.38; p = 0.49), VT (odds ratio 0.61, CI 0.08–4.90; p = 0.64) and VF (RR 0.49, CI 0.13–1.90; p = 0.30), but significantly more second-degree AVB (RR 7.88, CI 4.15–14.9; p < 0.01) in the adenosine group compared with the placebo group.

Conclusion: Intracoronary adenosine administration was well tolerated and significantly improved electrocardiographic outcomes with a tendency towards improvement in MACE, HF and CV mortality that could not reach statistical significance.

Prevention and treatment of microvascular obstruction-related myocardial injury and coronary no-reflow following percutaneous coronary intervention: a systematic approach

Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed "no-reflow." Microvascular obstruction can be broadly categorized according to the duration of myocardial ischemia preceding PCI. In "interventional MVO" (e.g., elective PCI), obstruction typically involves myocardium that was not exposed to acute ischemia before PCI. Conversely "reperfusion MVO" (e.g., primary PCI for acute myocardial infarction) occurs within a myocardial territory that was ischemic before the coronary intervention. Interventional and reperfusion MVO have distinct pathophysiological mechanisms and may require individualized therapeutic approaches. Interventional MVO is triggered predominantly by downstream embolization of atherosclerotic material from the epicardial vessel wall into the distal microvasculature. Reperfusion MVO results from both distal embolization and ischemia-reperfusion injury within the subtended ischemic tissue. Management of MVO and no-reflow may be targeted at different levels: the epicardial artery, microvasculature, and tissue. The aim of the present report is to advocate a systematic approach to prevention and treatment of MVO in different clinical settings. Randomized clinical trials have studied strategies for prevention of MVO and no-reflow; however, the efficacy of measures for reversing MVO once no-reflow has been demonstrated angiographically is unclear. New approaches for prevention and treatment of MVO will require a better understanding of intracellular cardioprotective pathways such as the blockade of the mitochondrial permeability transition pore.

How to manage no reflow phenomenon with local drug delivery via a rapid exchange catheter

We describe two cases of no reflow phenomenon in the setting of primary PCI for ST elevation myocardial infarction successfully managed with intracoronary vasodilator therapy via a Clearway™ balloon catheter, where vasodilator therapy via the guiding catheter had been ineffective. Traditionally, if not given via the guiding catheter, vasodilators have been administered via an over-the-wire balloon catheter, which can be cumbersome and time consuming. The Clearway catheter is a rapid exchange balloon catheter affording rapid delivery of vasodilators to the distal infarct related artery without risk of loss of wire position. © 2010 Wiley-Liss, Inc.

Pathogenesis of myocardial ischemia-reperfusion injury and rationale for therapy

Since the initial description of the phenomenon by Jennings et al 50 years ago, our understanding of the underlying mechanisms of reperfusion injury has grown significantly. Its pathogenesis reflects the confluence of multiple pathways, including ion channels, reactive oxygen species, inflammation, and endothelial dysfunction. The purposes of this review are to examine the current state of understanding of ischemia-reperfusion injury, as well as to highlight recent interventions aimed at this heretofore elusive target. In conclusion, despite its complexity our ongoing efforts to mitigate this form of injury should not be deterred, because nearly 2 million patients annually undergo either spontaneous (in the form of acute myocardial infarction) or iatrogenic (in the context of cardioplegic arrest) ischemia-reperfusion.

The pathogenesis and treatment of no-reflow occurring during percutaneous coronary intervention

No-reflow is one of the major causes of postinterventional rise of cardiac enzyme and myocardial infarction (MI). This complication is associated with substantial morbidity and mortality after percutaneous coronary intervention (PCI). During and after a no-reflow episode, the patient can suffer from severe chest pain, hypotension, bradycardia, hemodynamic collapse, MI, congestive heart failure, and death. Every effort should be taken to reduce the incidence of this complication. The distal embolic protection device has been shown to decrease this risk in saphenous vein graft (SVG) interventions but not in native coronaries. On the other hand, the use of glycoprotein IIb/IIIa receptor antagonists have been effective in reducing the occurrence of no-reflow during PCI of native coronaries but not during SVG interventions. The treatment of no-reflow is based on the intracoronary administrations of medications that induce maximal vasodilatation in small distal coronary vasculature. The most commonly used drugs in this setting are adenosine, nitroprusside, and verapamil. The goal of this study was to review the pathogenesis and treatment of no-reflow in patients undergoing PCI.

Management of 'no-reflow' complicating reperfusion therapy

No-reflow phenomenon, defined as inadequate myocardial perfusion of the adequately dilated target vessel without evidence of angiographic mechanical obstruction. It is a multifactorial, well-recognised, secondary phenomenon following reperfusion therapy such as thrombolysis or percutaneous coronary interventions (PCI). The pathophysiological mechanisms leading to the no-reflow state are incompletely understood. Embolization of the atheromatous material to the distal vasculature and intense arteriole vasospasm caused by microembolization of platelet-rich thrombi that release vasoactive agents resulting in microvascular obstructions are likely mechanisms. Current prophylaxis and management strategies are derived from limited clinical data. Intracoronary verapamil, adenosine and nitroprusside have been most frequently studied and administered for angiographic no-reflow during PCI for acute myocardial infarction or saphenous vein graft (SVG) lesions and have been shown to improve epicardial flow and microvascular perfusion. The use of distal embolic protection devices in SVG interventions also provide microvascular protection and improve clinical outcomes. However, by far the most important measures are prevention and anticipation during PCI as once no-reflow established, complete reversal of the situation may not be possible.

Intracoronary Vasodilators for the No-Reflow Phenomenon

Objective:

To review the literature relating to the use of intracoronary vasodilators to prevent and/or treat the no-reflow phenomenon in patients undergoing percutaneous coronary intervention (PCI).

Data Sources:

A literature search was conducted using MEDLINE (1966–March 2008) and Science Citation Index (1945–March 2008) using the search terms vasodilators, no-reflow, and intracoronary.

Study Selection and Data Extraction:

English-language clinical trials and case series were selected from articles retrieved. References of reviewed articles were examined for additional sources. Studies relating to the use of intracoronary vasodilators in the prevention and/or treatment of no-reflow in PCI were evaluated for safety and efficacy data. Articles relating to agents not available in the US were excluded.

Data Synthesis:

Evidence of intracoronary adenosine's utility in no-reflow treatment is limited. Its use in no-reflow prevention was associated with outcomes ranging from no difference to nearly an 88% reduction in no-reflow development; the drug was generally well tolerated. No-reflow treatment with intracoronary verapamil improved flow in 87–100% of cases. Preventive trials with verapamil failed to demonstrate efficacy. Atrioventricular block requiring treatment was the most commonly reported adverse event with intracoronary verapamil. Literature on intracoronary diltiazem and intracoronary nicardipine is limited. Both agents produced greater than 95% efficacy in no-reflow treatment, while prevention studies found no-reflow developing in less than 4% of patients. Although adverse event reporting was limited, hemodynamic instability was noted in patients receiving diltiazem. Response rates ranged from 73% to 100% when intracoronary nitroprusside was studied as treatment for no-reflow associated with acute myocardial infarction (AMI). Systemic hypotension was noted with nitroprusside administration.

Conclusions:

The available data are predominately from case series and retrospective reviews. Prevention of no-reflow with intracoronary vasodilators in elective PCI is not warranted. Nitroprusside should be considered first-line treatment in no-reflow associated with AMI.

Intracoronary boluses of adenosine and sodium nitroprusside in combination reverses slow/no-reflow during angioplasty: a clinical scenario of ischemic preconditioning

No or slow reflow following percutaneous coronary intervention (PCI), despite the presence of a patent epicardial vessel, is a serious complication resulting in increased morbidity and mortality. In the present study, we have evaluated the combination therapy of adenosine and sodium nitroprusside administered as sequential intracoronary (IC) boluses on no-reflow during PCI. Seventy-five high risk acute coronary syndrome patients who underwent PCI with evidence of initial less than TIMI (thrombolysis in myocardial infarction) III flow or developed deterioration in TIMI flow during the procedure were randomized to prophylactic administration of multiple boluses of IC saline solution, adenosine (12 microg/bolus) or the combination of adenosine (12 microg/bolus) and sodium nitroprusside (50 microg/bolus), sequentially. Assessment of TIMI and the TMP (tissue myocardial perfusion) grade was done and major adverse cardiac events (MACE) were assessed at the end of 6 months. Slow or no-reflow was persistent in 70% patients receiving saline solution, 31% patients receiving adenosine, and 4% patient receiving the combination. IC injection with saline solution did not produce improvement in TIMI flow or TMP grade. IC injection with combination resulted in greater improvement of TIMI flow and TMP grade. The crossover of patients with no-reflow in saline solution group or adenosine with combination treatment was associated with reestablishment of TIMI II in 4 and TIMI III in 20 patients. Our data suggest that combination therapy of adenosine and nitroprusside is safe and provides better improvement in coronary flow and MACE as compared with IC adenosine alone in cases of impaired flow during coronary interventions.

Efficacy of intracoronary nicardipine in the treatment of no-reflow during percutaneous coronary intervention

OBJECTIVES

The goal of this study was to evaluate the safety and efficacy of nicardipine in reversing no-reflow during percutaneous coronary intervention (PCI).

BACKGROUND

No-reflow is a common complication of PCI in patients with acute coronary syndromes or venous bypass graft disease. Although nicardipine has an attractive pharmacological profile and has been used clinically to treat no-reflow, there is a paucity of published data regarding its effectiveness in this setting.

METHODS

We conducted a retrospective analysis of 72 consecutive patients who received intracoronary nicardipine to reverse no-reflow during coronary intervention. Qualitative TIMI flow grade and quantitative TIMI frame count methods were used to assess the efficacy of nicardipine.

RESULTS

A mean of 460 +/- 360 mcg of intracoronary nicardipine was used. No-reflow was successfully reversed with complete restoration of TIMI 3 flow in 71 of 72 patients (98.6%). TIMI flow grade improved from 1.65 +/- 0.53 prior to nicardipine to 2.97 +/- 0.24 after treatment (P < 0.001). TIMI frame count decreased from 57 +/- 40 at the time of no-reflow to 15 +/- 12 after nicardipine administration (P < 0.001). Nicardipine therapy was well tolerated without adverse hemodynamic or chronotropic effects.

CONCLUSIONS

In this largest series to date, intracoronary nicardipine was demonstrated to be a safe and highly effective pharmacological agent to reverse no-reflow during PCI.

Intracoronary nitroprusside for the prevention of the no-reflow phenomenon after primary percutaneous coronary intervention in acute myocardial infarction. A randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

The aim of this study was to test whether nitroprusside (NTP) injected intracoronary immediately before primary angioplasty for acute ST-elevation acute myocardial infarction (STEMI) prevents no-reflow and improves vessel flow and myocardial perfusion.

METHODS

Ninety-eight patients presenting with STEMI were evenly randomized to receive either NTP (60 microg) or placebo. The drug was selectively injected into the infarct-related artery, distal to the occlusion, in a double-blind manner. The primary end points were postintervention angiographic corrected thrombolysis in myocardial infarction frame count and the proportion of patients with complete (>70%) ST-segment elevation resolution. Secondary end points included myocardial blush score and clinical outcome at 6 months follow-up.

RESULTS

Mean (+/-SD) age was 62 (+/-12) years, and 87% were men. Baseline characteristics (excluding sex) did not differ between groups. The corrected thrombolysis in myocardial infarction frame count after angioplasty was 20.8 (+/-18.6) and 20.3 (+/-21.3) in patients given NTP and placebo, respectively (P = .78). Complete ST-segment resolution was achieved in 61.7% and 61.2% of NTP and placebo subjects, respectively (P = .96). The distribution of myocardial blush score did not differ between groups. At 6 months, the rate of target lesion revascularization, myocardial infarction, or death occurred in 6.3% of the NTP group and 20.0% of the placebo group (P = .05).

CONCLUSIONS

In patients with STEMI, selective intracoronary administration of a fixed dose of NTP failed to improve coronary flow and myocardial tissue reperfusion but improved clinical outcomes at 6 months.

Impact of Reversibility of No Reflow Phenomenon on 30-Day Mortality Following Percutaneous Revascularization for Acute Myocardial Infarction-Insights from a 1,328 Patient Registry

BACKGROUND

Occurrence of no reflow phenomenon during percutaneous coronary intervention (PCI) is associated with increased mortality. Although intracoronary medications can improve coronary flow, the effect on mortality is not known.

METHODS

Patients who had PCI for myocardial infarction (MI) at the Singapore National University Hospital from January 2000 to March 2004 were studied. Our analysis stratified patients into three groups according to the occurrence and persistence of no reflow during PCI. (1) Adequate reflow: without no reflow occurrence; (2) Reversible no reflow: no reflow occurred, but final thrombolysis in myocardial infarction (TIMI) 3 flow restored after intracoronary medications; and (3) Refractory no reflow: no reflow occurred and persisted, final TIMI flow < 3 despite medications. Thirty-day mortality was determined for each group.

RESULTS

A total of 1,328 patients (82% male), 703 (53%) underwent primary PCI and 625 (47%) rescue PCI were analyzed. Among the study patients, no reflow (including reversible and refractory) occurred in 135 patients (10.2%). Intracoronary verapamil, adenosine, nitroprusside, or a combination of drugs were used to treat the no reflow in 70.0%, 17.7%, 3.5%, and 8.8% of cases, respectively. Intracoronary medications successfully restored final TIMI 3 in 108 patients (80%, reversible no reflow). The remaining 27 patients (20%) have final TIMI < 3 (refractory no reflow). In comparison with the adequate reflow and reversible no reflow groups, those with refractory no reflow had an increased 30-day mortality (3.7% vs 2.8% vs 32.0%, P < 0.001). Logistic regression analyses showed that patients with refractory no reflow had a significantly higher 30-day mortality compared to patients with adequate reflow (P < 0.001) and reversible no reflow (P = 0.001), but no significant differences in the 30-day mortality between patients with adequate reflow and reversible no reflow (P = 0.157) were detected after adjusting for relevant covariates.

CONCLUSION

Among patients undergoing PCI for MI, reversible no reflow was associated with a significantly lower 30-day mortality compared with the refractory counterpart.

Guidelines for percutaneous coronary interventions. The Task Force for Percutaneous Coronary Interventions of the European Society of Cardiology

In patients with stable CAD, PCI can be considered a valuable initial mode of revascularization in all patients with objective large ischaemia in the presence of almost every lesion subset, with only one exception: chronic total occlusions that cannot be crossed. In early studies, there was a small survival advantage with CABG surgery compared with PCI without stenting. The addition of stents and newer adjunctive medications improved the outcome for PCI. The decision to recommend PCI or CABG surgery will be guided by technical improvements in cardiology or surgery, local expertise, and patients' preference. However, until proved otherwise, PCI should be used only with reservation in diabetics with multi-vessel disease and in patients with unprotected left main stenosis. The use of drug-eluting stents might change this situation. Patients presenting with NSTE-ACS (UA or NSTEMI) have to be stratified first for their risk of acute thrombotic complications. A clear benefit from early angiography (<48 h) and, when needed, PCI or CABG surgery has been reported only in the high-risk groups. Deferral of intervention does not improve outcome. Routine stenting is recommended on the basis of the predictability of the result and its immediate safety. In patients with STEMI, primary PCI should be the treatment of choice in patients presenting in a hospital with PCI facility and an experienced team. Patients with contra-indications to thrombolysis should be immediately transferred for primary PCI, because this might be their only chance for quickly opening the coronary artery. In cardiogenic shock, emergency PCI for complete revascularization may be life-saving and should be considered at an early stage. Compared with thrombolysis, randomized trials that transferred the patients for primary PCI to a 'heart attack centre' observed a better clinical outcome, despite transport times leading to a significantly longer delay between randomization and start of the treatment. The superiority of primary PCI over thrombolysis seems to be especially clinically relevant for the time interval between 3 and 12 h after onset of chest pain or other symptoms on the basis of its superior preservation of myocardium. Furthermore, with increasing time to presentation, major-adverse-cardiac-event rates increase after thrombolysis, but appear to remain relatively stable after primary PCI. Within the first 3 h after onset of chest pain or other symptoms, both reperfusion strategies seem equally effective in reducing infarct size and mortality. Therefore, thrombolysis is still a viable alternative to primary PCI, if it can be delivered within 3 h after onset of chest pain or other symptoms. Primary PCI compared with thrombolysis significantly reduced stroke. Overall, we prefer primary PCI over thrombolysis in the first 3 h of chest pain to prevent stroke, and in patients presenting 3-12 h after the onset of chest pain, to salvage myocardium and also to prevent stroke. At the moment, there is no evidence to recommend facilitated PCI. Rescue PCI is recommended, if thrombolysis failed within 45-60 min after starting the administration. After successful thrombolysis, the use of routine coronary angiography within 24 h and PCI, if applicable, is recommended even in asymptomatic patients without demonstrable ischaemia to improve patients' outcome. If a PCI centre is not available within 24 h, patients who have received successful thrombolysis with evidence of spontaneous or inducible ischaemia before discharge should be referred to coronary angiography and revascularized accordingly--independent of 'maximal' medical therapy.

Incidence and Management of "No-Reflow" Following Percutaneous Coronary Interventions

No-reflow is a complex condition associated with inadequate myocardial perfusion of the coronary artery in the absence of epicardial obstruction. It can occur in several settings, including percutaneous coronary intervention, especially in complex thrombotic lesions of native arteries and vein grafts and in primary angioplasty. The causes of no-reflow are not completely understood, and current treatments consist of intracoronary vasodilators, antithrombotic therapies, and mechanical devices (including aspiration thrombectomy catheters and embolic protection devices).