Precautions (International)

CAUTION: Federal law (USA) restricts this device to sale by or on the order of a physician.

Prior to use, please see the complete “Instructions for Use” for more information on Indications, Contraindications, Warnings, Precautions, Adverse Events, and Operator’s Instructions.


The COBRA PzF NanoCoated Coronary Stent System is indicated for improving coronary luminal diameter in patients, including patients with diabetes mellitus, with symptomatic ischemic heart disease due to de novo lesions in native coronary arteries. The COBRA PzF NanoCoated stent is intended for use in patients eligible for percutaneous transluminal coronary angioplasty (PTCA) with reference vessel diameter (RVD) of 2.5-4.0mm and lesion length of ≤24mm.


The COBRA PzF NanoCoated Coronary Stent System is contraindicated for use in patients with:

  • known sensitivity to L605 cobalt-chromium alloy (including its major elemental constituents cobalt, chromium, tungsten, and/or nickel).
  • contraindication to coronary artery stenting:
  • Patients with lesions that may prevent complete inflation of an angioplasty balloon,  proper placement of the delivery device or stent deployment;
  • Patients are unable to receive recommended anti-platelet and/or anti-coagulant therapy.
  • known severe reaction to contrast agents that cannot be adequately pre-medicated prior to the COBRA PzF NanoCoated Coronary Stent System placement procedure.


  • Contents supplied sterile using an ethylene oxide (EO) process. Do not use if sterile barrier has been opened or is damaged prior to use.
  • This device is intended for single use only. Do not re-sterilize and/or reuse as this can potentially result in increased risk of inadequate sterilization, cross contamination and compromised device performance.
  • Use of this device carries the associated risks of stent thrombosis, vascular complications, and bleeding events. Judicious patient selection and administration of appropriate anticoagulant and anti-platelet therapy are necessary to reduce these risks.
  • When more than one stent is required, resulting in stent-to-stent contact, stent materials should be of similar composition to avoid the possibility of corrosion due to the presence of dissimilar metals in a conducting medium. The PzF SHIELD trial specified that lesions were to be covered with one stent of adequate length.  For bailout procedures or in the event of sub-optimal results, further stenting using the COBRA PzF Coronary Stent was left to investigator’s discretion.


Precautions: General

The risks and benefits of treatment with a coronary stent should be considered before using the COBRA PzF NanoCoated Coronary Stent System.

  • Only physicians who have received adequate training in stent placement should perform implantation of this device.
  • Stent placement should only be performed at hospitals where emergency coronary artery bypass graft surgery can readily be performed.
  • Do not use if labeling is incomplete or illegible.
  • The delivery system must not be exposed to organic solvents (e.g., alcohol or detergents)
  • Methods for safely treating in-stent restenosis of a COBRA PzF NanoCoated Stent (e.g., use of atherectomy devices or laser angioplasty catheters) have not been evaluated.
  • Subsequent development of in-stent restenosis may necessitate repeated dilatation within the arterial segment. Data regarding the outcome of repeated dilatation within re-endothelialized COBRA PzF NanoCoated Stents are not available.
  • Compared to use within the specified Indications for Use, the use of COBRA PzF NanoCoated stents in patients and lesions outside the labeled indications, including more tortuous anatomy, may have an increased risk of adverse events, including stent thrombosis, stent embolization, MI, or death.

Precautions: Pre- and Post-Procedure Antiplatelet Regimen

  • Appropriate anticoagulant/anti-platelet therapy should be administered according to current medical guidelines. For reference, the 2016 ACC/AHA Guidelines are provided at the following website:
  • In the PzF SHIELD trial, the protocol recommended aspirin indefinitely and recommended Clopidogrel, Prasugrel, Ticagrelor or Ticlopidine for a minimum of one (1) month post procedure.
  • It is very important that the patient comply with the post-procedural antiplatelet therapy recommendations. Early discontinuation of prescribed antiplatelet medication could result in a higher risk of thrombosis, MI, or death. Prior to percutaneous coronary intervention (PCI), if the patient is required to undergo a surgical or dental procedure that might require early discontinuation of antiplatelet therapy, the physician and patient should carefully consider whether a COBRA PzF NanoCoated Coronary Stent System and its associated recommended antiplatelet therapy is the appropriate PCI treatment of choice. Following PCI, should a surgical or dental procedure be necessary, requiring suspension of antiplatelet therapy, the risks and benefits of the procedure should be weighed against the possible risk associated with early discontinuation of antiplatelet therapy. Patients who require early discontinuation of antiplatelet therapy should be monitored carefully for cardiac events. At the discretion of the patient’s treating physicians, the antiplatelet therapy should be restarted as soon as possible.

Precautions: Use in Conjunction with Other Procedures

The safety and effectiveness of using mechanical atherectomy devices or laser angioplasty catheters in conjunction with the COBRA PzF NanoCoated Coronary Stent System implantation have not been established.

Precautions: Lesion / Vessel Characteristics

Safety and effectiveness of the COBRA PzF NanoCoated Coronary Stent System have not been established for subject populations with the following clinical settings:

  • Unresolved vessel thrombus at the lesion site
  • Coronary artery reference vessel diameters < 2.50 mm or > 4.00 mm
  • Lesion lengths > 24 mm or lesions requiring more than one COBRA PzF NanoCoated Coronary Stent
  • Lesions located in saphenous vein grafts
  • Lesions located in unprotected left main coronary artery, ostial lesions, and lesions located at bifurcations
  • Previously stented lesions
  • Diffuse disease or poor flow (TIMI < 1) distal to the identified lesions
  • Excessive tortuosity proximal to or within the lesion
  • Recent acute myocardial infarction (AMI) or evidence of thrombus in the target vessel
  • Multivessel disease
  • In-stent restenosis
  • Patients with a chronic total occlusion

Precautions: Magnetic Resonance Imaging (MRI)

The COBRA PzF NanoCoated

Stent is MR Conditional.

MR Conditional


Non-clinical testing demonstrated that the COBRA PzF NanoCoated Stent is MR Conditional for single and overlapping stents up to 58mm. A patient with this device can be scanned safely, immediately after placement under the following conditions:

  • Static magnetic field of 1.5-Tesla and 3.0-Tesla, only
  • Maximum spatial gradient magnetic field of 4,500-Gauss/cm (45 T/m) or less
  • Maximum MR system reported, whole body averaged specific absorption rate (SAR)
    of 4-W/kg (First Level Controlled Mode)

MRI Related Heating

Non-clinical testing, demonstrated that the COBRA PzF NanoCoated Stent is MR Conditional for single and overlapping stents and produced the following temperature rises during MRI performed for 15-min of scanning (i.e., per pulse sequence) in 1.5-Tesla/64-MHz (Magnetom, Siemens Medical Solutions, Malvern, PA. Software Numaris/4, Version Syngo MR 2002B DHHS Active-shielded, horizontal field scanner) and 3-Tesla/128-MHz(Excite, HDx, Software 14X.M5, General Electric Healthcare, Milwaukee, WI) MR systems:

1.5-Tesla 3-Tesla
MR system reported, whole body averaged SAR 2.9-W/kg 2.9-W/kg
Calorimetry measured values, whole body averaged SAR 2.1-W/kg 2.7-W/kg
Highest temperature change 2.6 °C 3.0 °C
Temperature scaled to whole body averaged SAR of 4-W/kg 3.6 °C 4.1 °C


The effect of heating in the MRI environment for stents with fractures is not known.


Artifact Information

MR image quality may be compromised if the area of interest is in the exact same area or relatively close to the position of the COBRA PzF NanoCoated Stent. Therefore, optimization of MR imaging parameters to compensate for the presence of this device may be necessary. The maximum artifact size (i.e., as seen on the gradient echo pulse sequence) extends approximately 5-mm relative to the size and shape of this implant. The lumen of this stent cannot be visualized using these pulse sequences.

Precautions: Stent Handling

  • Each stent is for single use only. Do not resterilize or reuse this device. Note the “Use By” (expiration) date on the product label.
  • The delivery system should not be used in conjunction with other stents.
  • Use caution to not disrupt the pre-mounted stent during removal of the delivery balloon from the packaging, placement over the guidewire, or advancement through hemostasis valve into the guide catheter.
  • Do not touch, handle, manipulate (“roll” or twist), or remove the pre-mounted stent as this may cause contamination, stent damage and/or dislodgement from the delivery balloon. These components are intended to perform together as a system.
  • Do not suspend the pre-mounted stent within a solution on the sterile field.
  • Use only the appropriate inflation medium (i.e., 1:1 solution by volume of contrast medium and saline). Never use air or other gaseous medium to inflate the balloon.

Precautions: Stent Placement

Precautions: Stent Preparation

  • Do not pre-inflate the delivery system prior to stent deployment.
  • When introducing the stent delivery system into a vessel, do not induce negative pressure on the delivery system as this may cause stent dislodgement from the balloon.
  • Use guiding catheters which have lumen sizes that are suitable to accommodate the stent delivery system (see section 1.1 Device Component Description).

Precautions: Stent Implantation

  • The decision to pre-dilate the lesion with an appropriate size balloon should be carefully based on patient and lesion characteristics.
  • The COBRA PzF NanoCoated stent should be positioned using standard angiographic techniques under direct visualization using high-resolution fluoroscopy.
  • Do not expand the stent if it is not properly positioned in the vessel. Once deployment begins, the stent cannot be repositioned.
  • Do not attempt to pull an unexpanded stent retrogradely through guiding catheter (See Section 6.8 for Precautions: Stent System Removal)
  • The delivery system should not be rotated during the deployment procedure. Do not rotate the delivery system by more than one rotation in either direction during use.
  • Stent implantation may lead to vessel dissection and may cause abrupt closure necessitating further intervention (e.g., CABG, additional dilatation and/or stent placement, or other).
  • Balloon pressures should be monitored during inflation. Do not exceed the rated burst pressure (RBP) as indicated on the product label.  Use of pressures higher than product label specifications may result in a ruptured balloon causing possible intimal damage and dissection.
  • Stent implantation has the potential to compromise side branch patency.

Precautions: Stent System Removal

  • Remove the entire system as a single unit if:

o   Unable to cross the lesion easily.

o   Resistance is encountered anytime during either stent advancement across the lesion or removal of the delivery catheter after deployment.

·         If removal of an unexpanded stent from the patient is required, do not pull the underdeployed stent retrogradely into the guide catheter. Perform the following:

1.    Advance the coronary guidewire as far distally into the coronary vasculature as safely possible.  The stent/balloon catheter should be withdrawn until the proximal end of the stent is aligned with the distal end of the guide catheter.

2.    Tighten the hemostatic valve to secure the delivery system to the guide catheter.

3.    The guide catheter, stent/balloon catheter system, and guidewire should then be removed as one unit through the introducer sheath.

Failure to follow these steps and/or applying excessive force on the delivery system may result in damage to, or loss of, the stent and/or delivery system components.

  • Stent retrieval methods (e.g., use of additional wires, snares and/or forceps) may result in additional trauma to the coronary vasculature and/or the vascular access site. Complications may include bleeding, hematoma, pseudoaneurysm, or perforation.
  • If the balloon ruptures during stent expansion, withdraw the balloon and exchange for a new balloon catheter to complete stent deployment.

Precautions: Post Deployment

  • Use caution when crossing a newly deployed stent with a coronary guidewire, balloon, delivery system, or intravascular ultrasound to avoid disruption of stent geometry and stent migration/dislodgement.
  • If patient requires imaging, see Section 6.5 Precautions: Magnetic Resonance Imaging (MRI)

Potential Adverse Events

Potential adverse events associated with stent placement include, but are not limited to:

  • Abrupt closure
  • Access site pain, hematoma, or hemorrhage
  • Allergic/reactions (including to contrast media, stent materials or medication)
  • Angina
  • Aneurysm (Coronary)
  • Arteriovenous fistula
  • Arrhythmias, including ventricular tachycardia or fibrillation
  • Bleeding
  • Cardiac tamponade
  • Cardiogenic shock
  • Cardiomyopathy
  • Death
  • Emboli (including air, tissue, plaque, thrombus or device materials)
  • Failure to deliver stent to intended site
  • Heart failure
  • Hematoma
  • Hypotension and/or hypertension
  • Infection, local and/ or systemic
  • ischemia, myocardial
  • Myocardial infarction
  • Pericardial effusion
  • Pseudoaneurysm
  • Pulmonary edema
  • Renal insufficiency or failure
  • Respiratory failure
  • Restenosis of the stented segment
  • Shock
  • Stent fracture or deformation
  • Stent migration
  • Stent thrombosis
  • Stroke or transient ischemic attack (TIA)
  • Total vessel occlusion
  • Vessel spasm
  • Vessel injury (including dissection, perforation, rupture or trauma)