{'fraction_non_alphanumeric': 0.022758812101026923, 'fraction_numerical': 0.014016097696364142, 'mean_word_length': 5.2669565217391305, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Elective percutaneous coronary intervention performed during contrast‐induced hypotension

To demonstrate the feasibility and safety of performing elective percutaneous coronary intervention (PCI) during contrast reaction producing severe hypotension.

several years earlier referred for stable angina (CCS II) ( Table 1).
Patient had recently been admitted for heart failure during which time urinary retention developed requiring indwelling Foley catheter. Prostate surgery was deferred until the cardiac issue was resolved.
Catheterization performed via radial access showed in-stent LAD chronic total occlusion (CTO) with no significant lesions elsewhere.
PCI was unsuccessful using 6 Fr guide catheter with only partial guide wire passage and in-stent balloon dilation. It was felt that backup support was insufficient. Plan was to bring patient back for femoral access using 8 Fr guide catheter and longer access sheath. The procedure used 248 mL of contrast (iodixanol) and was well tolerated.
The patient returned 6 weeks later. Initial non-invasive blood pressure was 154/83 mm Hg. Using micropuncture technique under ultrasound guidance, right femoral artery was accessed with angiography (iodixanol) showing sheath in the common femoral artery without evidence of extravascular contrast leakage. The first direct blood pressure measurement was 60/40 mm Hg with heart rate of 40 bpm; the patient was asymptomatic. Patient immediately received 50 mcg intravenous (iv) phenylephrine and 1 mg atropine. It was felt that patient was having a severe contrast reaction; 100 mcg of intravenous epinephrine, 125 mg of IV methylprednisolone and 25 mg IV diphenhydramine were administered. Systolic pressure increased to approximately 170 mm Hg but gradually decreased to 80 mm Hg requiring additional 100 mcg epinephrine. The procedure was terminated. Patient was started on IV epinephrine drip (6 mg/min), observed for several hours with satisfactory blood pressure and discharged approximately 8 h later.
The patient was brought back 4 months later. Patient had been premedicated with oral prednisone 60 mg Â3 doses at 13, 7, and 1 h pre-procedure. The patient was given 25 mg oral diphenhydramine and 120 mg iv methylprednisolone immediately prior to first dye injection.
Femoral access was obtained using micropuncture technique under ultrasound assistance with angiogram (iodixanol) confirming common femoral access without dye extravasation. An 8 Fr XB 3.5 guide catheter was passed to the ascending aorta where initial pressure was 64/37 mm Hg. The patient remained asymptomatic. Based on knowledge of patient's contrast history, 500 mcg of epinephrine, 500 mL bolus of normal saline, and 125 mg iv methylprednisolone were immediately given. Blood pressure rose to 200/100 mm Hg. Although patient had had a previous hypotensive reaction to contrast, as he remained asymptomatic after rapid (<1 min) restoration of blood pressure, it was decided to proceed with PCI. Patient needed 100 mcg epinephrine twice during PCI when blood pressure decreased to 80/60 mm Hg. An epinephrine drip at 1 mg/min was started and titrated to a maximum of 8 mg/min. Patient remained stable and successful PCI of LAD CTO lesion was performed. Following PCI, epinephrine drip was tapered over next 12 h. The patient was discharged the following day.   The primary message of the current report is that in some cases coronary intervention can still be performed during a contrast reaction. In fact, in patients with a known contrast reaction, one can plan to perform an elective intervention as seen in these three patients who underwent a total of nine successful PCI procedures while being hemodynamically supported during a contrast reaction. This report is the first to describe planned interventions in the setting of a previously known contrast reaction causing hypotension with successful PCI despite recurrent hypotension requiring pharmacological support.
A previous report suggested the possibility of performing intervention during interventional procedures but profound hypotension was not described in any of the 11 reported patients. 3 That PCI can be performed as in the described cases does not imply it should always, or even frequently, be performed. However, under appropriate circumstances it may be considered. We suggest that the most important factors relate to the time required to adequately treat the hypotension, the patient's co-morbidities, patient's comfort level, and the criticality of performing the coronary intervention ( Figure 1). If the patient's hypotension can be reversed quickly, that is, within a minute, and the blood pressure can be maintained with reasonable pressor support, it is suggested that the risk of end organ dysfunction, for example, acute renal failure, should be low. In that circumstance, if it is felt that PCI is the most appropriate treatment and the patient is comfortable, consideration of continuing the procedure seems reasonable.
If, on the other hand, developing hemodynamic stability requires a prolonged period, for example, greater than 10 min, or blood pressure cannot be maintained adequately with pressor then terminating the procedure and following for end-organ dysfunction seems most reason- Although pre-treatment with steroids and antihistamines in patients with previous contrast reactions is recommended by current ACC AHA guidelines, evidence that these medications can prevent repeat severe reaction is scanty. 1,2,4 The present cases highlight that pre-treatment is not necessarily protective. Although these agents may be used, the operator must be aware that they may be ineffective and be vigilant to rapid treatment for a repeat contrast reaction.
The present case series also emphasizes the vagaries of a severe contrast reaction. In these three cases, once the patient had developed a contrast reaction, it occurred in most cases. However, in one of the procedures in Patient 3, PCI was performed without a reaction despite no pre-medication. It is also interesting that in the three patients, all had initial angiography without reaction, suggesting the possibility that initial exposure created an undetermined IgE antibody producing the subsequent reaction. 1 Finally, the possibility of a "contrast-less" intervention may be considered for repeat intervention. 5 When coronary anatomy is known from a previous angiogram, the use of intravascular imaging may allow for PCI without contrast. Ali and colleagues demonstrated in 31 chronic kidney disease patients the feasibility of performing focused coronary intervention without any dye use. 5

| CONCLUSION
This case series demonstrates that elective PCI can be performed during a severe contrast reaction producing hypotension. It is recommended that if certain conditions are fulfilled, PCI may be considered despite an ongoing anaphylactoid reaction. These conditions include (a) rapid treatment initially preventing prolonged hypotension and subsequent risk of organ damage, (b) blood pressure easily modulated by iv epinephrine, (c) the patient being comfortable and asymptomatic during the contrast reaction, and (d) that PCI is the most appropriate therapeutic option.