Extending Time to Reperfusion with Mild Therapeutic Hypothermia: A New Paradigm for Providing Primary Percutaneous Coronary Intervention to Remote ST Segment Elevation Myocardial Infarction Patients.

Primary percutaneous coronary intervention (PPCI) is the preferred treatment for acute ST segment elevation myocardial infarction (STEMI). The goal is reperfusion within 90 minutes of first medical contact (FMC) or 120 minutes if transfer is needed. Otherwise, fibrinolytic therapy is recommended. Mild therapeutic hypothermia (MTH) (≤35°C) before coronary reperfusion decreases myocardial infarct size. If applied before reperfusion, hypothermia could potentially lengthen the FMC-reperfusion time without increasing infarct size. Thirty-six swine had their mid left anterior descending coronary artery acutely occluded. All animals had an initial 30 minutes of occlusion to simulate typical delay before seeking medical attention. Eighteen animals were studied under normothermic conditions with reperfusion after an additional 40 minutes (the porcine equivalent of a 120-minute clinical FMC to reperfusion time) and 18 were treated with hypothermia but not reperfused until another 80 minutes (clinical equivalent of 240 minutes). Primary outcome was myocardial infarct size (infarct/area at risk [AAR]) at 24 hours. The two groups differed in systemic temperature at the time of reperfusion (39.1°C ± 1.0°C vs. 35.5°C ± 0.7°C; p < 0.0001). Myocardial infarct size was not significantly different despite the longer time to reperfusion in those treated with hypothermia (60.6% ± 12% of the AAR [normothermic] vs. 65.8% ± 11.8% of the AAR [hypothermic]; p = 0.39). Rapid induction of MTH during an anterior STEMI made it possible to extend the FMC to reperfusion time by the equivalent of an extra two clinical hours (120-240 minutes) without increasing the myocardial infarct size. This strategy could allow more STEMI patients to receive PPCI rather than the less effective intravenous fibrinolysis.

Stent-Only Versus Adjunctive Balloon Angioplasty Approach for Saphenous Vein Graft Percutaneous Coronary Intervention: Insights From DIVA Trial.

BACKGROUND: Direct stenting without pre-dilation or post-dilation has been advocated for saphenous vein graft percutaneous coronary intervention to decrease the incidence of distal embolization, periprocedural myocardial infarction, and target lesion revascularization. METHODS: We performed a post hoc analysis of patients enrolled in the DIVA (Drug-Eluting Stents Versus Bare Metal Stents in Saphenous Vein Graft Angioplasty; NCT01121224) prospective, double-blind, randomized controlled trial. Patients were stratified into stent-only and balloon-stent groups. Primary end point was 12-month incidence of target vessel failure (defined as the composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization). Secondary end points included all-cause death, stent thrombosis, myocardial infarction, and target lesion revascularization during follow-up. RESULTS: Of the 575 patients included in this substudy, 185 (32%) patients underwent stent-only percutaneous coronary intervention. Patients in the stent-only versus balloon-stent group had similar baseline characteristics and similar incidence of target vessel failure at 12-months (15% versus 19%; hazard ratio, 1.34 [95% CI, 0.86-2.08]; P=0.19). During long-term follow-up (median of 2.7 years), the incidence of definite stent thrombosis (1% versus 5%; hazard ratio, 9.20 [95% CI, 1.23-68.92]; P=0.0085), the composite of definite or probable stent thrombosis (5% versus 11%; hazard ratio, 2.52 [95% CI, 1.23-5.18]; P=0.009), and target vessel myocardial infarction (8% versus 14%; hazard ratio, 1.92 [95% CI, 1.08-3.40]; P=0.023) was lower in the stent-only group. Multivariable analysis showed that a higher number of years since coronary artery bypass grafting and >1 target saphenous vein graft lesions were associated with increased target vessel failure during entire follow-up, while preintervention Thrombolysis in Myocardial Infarction-3 flow was protective. CONCLUSIONS: In patients undergoing percutaneous coronary intervention of de novo saphenous vein graft lesions, there was no difference in target vessel failure at 12 months and long-term follow-up in the stent-only versus the balloon-stent group; however, the incidence of stent thrombosis was lower in the stent-only group, as was target vessel myocardial infarction. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01121224.

Cardiac Arrest in the Cardiac Catheterization Laboratory: Combining Mechanical Chest Compressions and Percutaneous LV Assistance.

OBJECTIVES: The aim of this study was to evaluate the optimal treatment approach for cardiac arrest (CA) occurring in the cardiac catheterization laboratory. BACKGROUND: CA can occur in the cath lab during high-risk percutaneous coronary intervention. While attempting to correct the precipitating cause of CA, several options are available to maintain vital organ perfusion. These include manual chest compressions, mechanical chest compressions, or a percutaneous left ventricular assist device. METHODS: Eighty swine (58 ± 10 kg) were studied. The left main or proximal left anterior descending artery was occluded. Ventricular fibrillation (VFCA) was induced and circulatory support was provided with 1 of 4 techniques: either manual chest compressions (frequently interrupted), mechanical chest compressions with a piston device (LUCAS-2), an Impella 2.5 L percutaneously placed LVAD, or the combination of mechanical chest compressions and the percutaneous left ventricular assist device. The study protocol included 12 min of left main coronary occlusion, reperfusion, with defibrillation attempted after 15 min of VFCA. Primary outcome was favorable neurological function (CPC 1 or 2) at 24 h, while secondary outcomes included return of spontaneous circulation and hemodynamics. RESULTS: Manual chest compressions provided fewer neurologically intact surviving animals than the combination of a mechanical chest compressor and a percutaneous LVAD device (0% vs. 56%; p < 0.01), while no difference was found between the 2 mechanical approaches (28% vs. 35%: p = 0.75). Comparing integrated coronary perfusion pressure showed sequential improvement in hemodynamic support with mechanical devices (401 ± 230 vs. 1,337 ± 905 mm Hg/s; p = 0.06). CONCLUSIONS: Combining 2 mechanical devices provided superior 24-h survival with favorable neurological recovery compared with manual compressions during moderate duration VFCA associated with an acute coronary occlusion in the animal catheterization laboratory.

Drug-coated balloon in peripheral artery disease.

Peripheral artery disease (PAD) is highly prevalent but is often underdiagnosed and undertreated. Lower extremity PAD can often be life style limiting. Revascularization in carefully selected lower extremity PAD patients improves symptoms and functional status. Surgical revascularization used to be the only available strategy, but in the recent years, endovascular strategies have gained popularity due to faster recovery times with low morbidity and mortality rates. Endovascular procedures have increased significantly in the United States in the past few years. That being said, higher restenosis rates and low long-term patency rates have been the limiting factors for this strategy. Drug eluting stents have been introduced to help with lowering restenosis, however lower extremity PAD involves long segment where the outcomes of stents are suboptimal. Also, the disease often crosses joint line that makes it less ideal for the stents. Drug-coated balloons (DCB) have been introduced to improve patency rates following endovascular intervention for lower extremity PAD. They have gained popularity among endovascular specialists due to its ease of use and the concept of "leave nothing behind". This is a review of scientific evidence supporting DCB use in PAD.

Cardiac Arrest in the Catheterization Laboratory.

BACKGROUND: Cardiac arrest in the Catheterization Lab is a rare and unique scenario that is often logistically challenging. It often has dire prognosis especially in patients suffering from severe pre-existing illnesses (high risk patient) such as acute myocardial infarction with cardiogenic shock, or patients undergoing high risk procedures. As the number of complex interventional procedures increases, cardiac arrest in the cath lab will become more common and optimal management of this scenario is critical for both the patient and operator. CONCLUSION: In this review, we will discuss the special challenges during the resuscitation efforts in cath lab, especially with tradition chest compression. We will discuss the alternative options including mechanical compression devices and Invasive Percutaneous Mechanical Circulatory Support Devices. Finally, we will offer management suggestions on selecting the appropriate circulatory support device based on clinical and anatomic risks.

Contemporary Use of Laser During Percutaneous Coronary Interventions: Insights from the Laser Veterans Affairs (LAVA) Multicenter Registry.

BACKGROUND: The contemporary use and outcomes of excimer laser coronary atherectomy (ELCA) in percutaneous coronary intervention (PCI) are not well described. METHODS: We examined the baseline clinical and angiographic characteristics and procedural outcomes of 130 target lesions in 121 consecutive PCIs (n = 116 patients) in which ELCA was performed at three United States Department of Veterans Affairs (VA) medical centers between 2008 and 2016. RESULTS: Mean age was 68.5 ± 9 years and 97% of the patients were men. Patients had high prevalence of diabetes mellitus (63%), prior coronary artery bypass graft surgery (41%), and prior myocardial infarction (60%). The most common target vessel was the left anterior descending (32%), followed by the right coronary artery (30%), circumflex artery (20%), and saphenous vein graft (12%). The target lesions were highly complex, with moderate/severe calcification in 62% and in-stent restenosis in 37%. The most common indication for ELCA was balloon-uncrossable lesions (43.8%), followed by balloon-undilatable lesions (40.8%) and thrombotic lesions (12.3%). Use of ELCA was associated with high technical success rate (90.0%) and procedural success rate (88.8%), and low major adverse cardiac event (MACE) rate (3.45%). Mean procedure time was 120 min (interquartile range [IQR], 81-191 min), air kerma radiation dose was 2.76 Gy (IQR, 1.32-5.01 Gy), and contrast volume was 273 mL (IQR, 201-362 mL). CONCLUSION: In a contemporary multicenter United States registry, ELCA was commonly used in highly complex lesions and was associated with high technical and procedural success rates and low incidence of MACE.

Insertion of the Impella via the axillary artery for high-risk percutaneous coronary intervention.

Hemodynamic support with the Impella device is an important tool during high risk percutaneous coronary intervention. This device is usually inserted via the femoral artery. However, some patients have severe peripheral artery disease precluding the use of the femoral artery for this purpose. The axillary artery is a viable alternative in these cases. We reviewed the two access techniques for inserting the Impella via the axillary artery and also described 6 cases of successful implantation.

Current Approaches to Cardiopulmonary Resuscitation.

Real progress has been made in improving long-term outcome after out-of-hospital cardiac arrest in the past 10 years. Many communities have doubled their survival-to-hospital-discharge rate during this period. Common features of such successful programs include the following: (1) 911 dispatcher-assisted cardiopulmonary resuscitation (CPR) instruction, (2) bystander chest compression-only CPR program, (3) public access defibrillation, including targeted automated external defibrillator programs, (4) renewed emphasis on minimally interrupted chest compressions by emergency medical services responders, and (5) aggressive postresuscitation care, including targeted temperature management and early coronary angiography and intervention. An important lesson from these successful community efforts is that multiple, simultaneous changes to the local cardiac arrest response system are necessary to improve survival. The next exciting step in this quest appears to be the treatment of refractory cardiac arrest with the combination of mechanical CPR, intra-arrest hypothermia, extracorporeal CPR with mechanical circulatory support devices, and early coronary intervention.

Beat-to-beat corrected QT analysis detects corrected QT prolongation in 50 consecutive telemetry-monitored patients.

BACKGROUND: The American Heart Association/American College of Cardiology Foundation recommends monitoring for corrected QT (QTc) prolongation. The incidence of QTc prolongation in the general public is unknown. Episodic measurements may miss patients at risk. OBJECTIVE: The purpose of this study was to determine the incidence of QTc prolongation in hospitalized telemetry patients when beat-to-beat monitoring, confirmed by manual calculation, was used for detection. METHODS: After institutional review board approval was obtained, waveforms of telemetry-monitored patients were analyzed consecutively until 50 patients with prolonged QTc were identified (QTc >470 milliseconds in men and >480 milliseconds in women). Prolongation was confirmed by manual calculation. Incidence was calculated. Clinical risk factors and the outcomes of torsades de pointe or sudden death were explored. RESULTS: Telemetry waveforms were evaluated for 192 444 minutes (3207.4 hours) of recordings, yielding 8,076,653 QTc measurements. In 50 consecutive patients (24 [48%] men), 100% had verified episode(s) of QTc prolongation. Home medications that could result in QTc prolongation were identified in 9 patients (18%). Hospital medications with risk of QTc prolongation were administered to 31 patients (62%). Sixteen patients (32%) were not on a QTc-prolonging medication. Corrected QT prolongation risk factors in the history were found in 2 patients (4%) and hypomagnesemia or hypokalemia was seen in 6 patients (12%). Twelve-lead electrocardiogram detected prolonged QTc in 13 of 45 patients (26%). Prolongation of QTc was detected by standard of care manual analysis in 4 patients (8%). No patient experienced torsades de pointe or sudden death. CONCLUSION: With beat-to-beat analysis, QTc prolongation was detected in 100% of 50 consecutive patients where standard of care (nursing manual analysis or 12-lead electrocardiogram) would have detected 28%. Hospital medications were more likely to contribute to QTc prolongation than home medications. IMPLICATIONS FOR PRACTICE: More specific definitions for determining proarrhythmic risk are needed as automated technology improves the capture rate of QTc prolongation events.