Ammar Nasir - Academia.edu (original) (raw)

Papers by Ammar Nasir

Research paper thumbnail of The Effect of Routine Coronary CT Angiogram Prior to Invasive Coronary Angiography Compared to Invasive Coronary Angiography Alone on Contrast Dose, Procedure Time, Radiation Dose, and Contrast Induced Nephropathy Among Patients with Prior Cabg: A Meta-Analysis of Prospective Studies

Journal of the American College of Cardiology, Mar 1, 2023

Research paper thumbnail of Atrial Fibrillation as Predictor of Outcomes in Patients with Spontaneous Coronary Artery Dissection

Journal of the American College of Cardiology

Research paper thumbnail of Use of Cerebral Embolic Protection Device is Associated with Improved Survival Amongst Patients Undergoing Transcatheter Aortic Valve Replacement: Updated Meta-Analysis

Journal of the American College of Cardiology

Research paper thumbnail of Regional and Temporal Variations in the Incidence of Spontaneous Coronary Artery Dissection (Scad): Insights from the National Inpatient Sample (Nis)

Journal of the American College of Cardiology

Research paper thumbnail of Pulmonary Hypertension as a Predictor for Increased Mortality in Patients Undergoing Percutaneous Left Atrial Appendage Occluder Device Placement

Journal of the American College of Cardiology

Research paper thumbnail of Troubleshooting an Impella- Novel Snaring Technique for De-Kinking the Impella CP

Journal of the American College of Cardiology

Research paper thumbnail of Abstract 13615: Mortality Trends And Regional Variations Of Aortic Aneurysm And Dissection In The United States

Circulation

Introduction: Aortic dissection and aortic aneurysm represent significant health risk as they are... more Introduction: Aortic dissection and aortic aneurysm represent significant health risk as they are associated with very high mortality. Incidence of aortic dissection is low and estimated to be 5-30/100,000 hospitalized patients. Similarly, aortic aneurysms have low incidence (depending upon location) and high mortality (over 80%). Combined mortality associated with aortic aneurysm or dissection and its contemporary trends in the U.S. are not well known. Methods: In this retrospective study death certificate data were retrieved from the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (WONDER) database for 1999-2018. Mortality for aortic aneurysm and dissection ICD-10 code-I71 as an underlying cause of death were queried from 1999-2018. This duration was further stratified into five-year periods. WONDER database is publicly available de-identified data collected by CDC that reports the underlying cause of death across the United States....

Research paper thumbnail of Abstract 13606: Is Pulmonary Hypertension a Poor Prognostic Sign in Patients Hospitalized for Transcatheter Aortic Valve Replacement

Circulation

Introduction: Pulmonary hypertension (PH) is common in patients with severe aortic stenosis (AS).... more Introduction: Pulmonary hypertension (PH) is common in patients with severe aortic stenosis (AS). The prevalence of PH in transcatheter aortic valve replacement (TAVR) patients is reported upto 78% and causes significant morbidity and mortality. We queried the National Inpatient Sample (NIS) database to explore the different outcomes of patients hospitalized for TAVR with and without the history of PH. Hypothesis: PH may increase mortality in hospitalized patients undergoing TAVR. Methods: This is a retrospective cohort study utilizing the 2016-2017 National Inpatient Sample. We identified patients hospitalized for TAVR with and without the history of PH using ICD10 codes. The primary outcome was inpatient mortality. The secondary outcomes were cost of hospitalization, and length of stay (LOS). Multivariate regression was used to adjust for potential confounders including age, gender, race, pulmonary embolism, acute coronary syndrome, heart block, left bundle branch block (LBBB), di...

Research paper thumbnail of Regional Variations in Premature Cardiovascular Mortality, 1999-2018

Journal of the American College of Cardiology

Research paper thumbnail of Premature Mortality in Males Due to Heart Failure in the United States from 2010-2018

Journal of the American College of Cardiology, Mar 1, 2022

Research paper thumbnail of Comparison of Outcomes for Non-ST Elevation Acute Myocardial Infarction in Weekday vs Weekend Admissions: The Weekend Effect

Journal of Community Hospital Internal Medicine Perspectives

Background: Recent literature shows that reduced staffing over the weekends in hospitals may comp... more Background: Recent literature shows that reduced staffing over the weekends in hospitals may compromise patient care with acute conditions like acute coronary syndrome (ACS). Objective: Our study evaluated differences in the outcomes between patients presenting with non-ST segment elevation acute coronary syndrome (NSTE-ACS) on weekends versus those coming on weekdays. Methods: A single-center retrospective study was performed on NSTE-ACS patients. Data were analyzed using SPSS version 22 to calculate an independent sample t-test value for significance between the two groups. Results: The mean DTB time for patients admitted over the weekend was significantly higher than those admitted over weekdays (p ¼ 0.000). The mean peak troponin level and length of stay (LOS) for patients admitted over the weekends vs. weekdays was significantly higher by 5 ng/dL (9.71 ± 5.23 vs. 4.194 ± 2.60, p ¼ 0.0001) and 24 h (72 ± 10 vs. 48 ± 6 h, p ¼ 0.003), respectively. While the mean left ventricular ejection fraction (EF) of patients on discharge was lower by 5% for patients admitted over the weekend compared to patients admitted on weekdays (p ¼ 0.001). Conclusion: NSTE-ACS patients admitted over the weekends have a significantly higher myocardial injury evidenced by an increased LOS, higher peak troponin levels, and reduced EF due to delayed PCI compared to weekday admissions.

Research paper thumbnail of Racial Disparities in Outcomes of Arrhythmias Among Patients Undergoing Transcatheter Aortic Valve Replacement: A National Population Based Study

Journal of the American College of Cardiology, 2021

Research paper thumbnail of One Case, Many Options

Research paper thumbnail of A Survey Paper on Security Issues in Satellite Communication Network infrastructure

Satellite communication is one of the most popular next generation communication technologies for... more Satellite communication is one of the most popular next generation communication technologies for global communication networks in parallel to terrestrial communication networks. In modern age military intelligence, navigation & positioning, weather forecasting, digital video Broadcasting (DVB), and broadband internet services, are the few demanding applications of Satellite communication. Although Satellite communication is cost effective solution for such long distance communication application, However security over the link is still a major concern in satellite communication. Due to limitations such as high bit error rate, power control, large distance between end nodes, high link delays because of large round trip times, and link availability, common security techniques incorporate a lot of issues in implementation of proper secure communication over the satellite links. In this survey paper, we explore the importance of security, trivial and currently deployed security tools, ...

Research paper thumbnail of Symptomatic high-risk congenital coronary anomaly

Heart and Mind, 2017

Anomalous coronary arteries are rare entities with certain categories being potentially malignant... more Anomalous coronary arteries are rare entities with certain categories being potentially malignant with the risk of sudden cardiac death. We present two cases of the highest risk variant consisting of an anomalous left coronary artery arising from the right sinus of Valsalva traversing between the aorta and pulmonary artery leading to recurrent syncope and chest pain in middle-aged patients.

Research paper thumbnail of Realization of Proportional-Integral Stirring Controller for Mixing Operation in Microbioreactor

In this paper, we presented the establishment of a cheap and simple stirring platform for microbi... more In this paper, we presented the establishment of a cheap and simple stirring platform for microbioreactor operation. The stirring platform was designed to provide necessary mixing via magnetic stirrer bar for a microbioreactor setup. The microbioreactor (volume ~ 300 L) used in this investigation was fabricated out of the poly(methylmethacrylate) (PMMA) polymer material via micromachining. Programs for the control routines were written in LabVIEW TM software (National Instruments, Austin, TX, USA), and were implemented by interfacing the LabVIEW TM programs with a data acquisition (DAQ) card (NI USB-6343, National Instruments, Austin, TX, USA) for data logging and sending signals to actuators. The paper first described the details of the mechanical design of the stirring platform and the microbioreactor prototype used in the work. Secondly, experimental results obtained to assess the mixing quality of the reactor and to characterize the performance of the controller in terms of con...

Research paper thumbnail of 859: Intensive Care Units with High Versus Low Annual Volume of Acute Myocardial Infarction

Critical Care Medicine, 2012

Research paper thumbnail of Utility of Radiopaque Bypass Graft Markers During Coronary Angiography Following Coronary Artery Bypass Graft Surgery

The Journal of invasive cardiology, 2020

BACKGROUND Radiopaque bypass graft markers allow easy visualization of the location of the graft ... more BACKGROUND Radiopaque bypass graft markers allow easy visualization of the location of the graft and can minimize contrast use and radiation exposure during follow-up coronary angiography. METHODS This retrospective study analyzed coronary artery bypass graft patients who underwent subsequent coronary angiography in the John Cochrane Veterans Affairs Medical Center from January 2009 until September 2017. RESULTS Patients who underwent diagnostic coronary angiography with proximal graft markers required less contrast use (P<.02) and less fluoroscopy time (P<.01). The presence or absence of proximal graft markers had no significant difference on the rise of creatinine following coronary angiography (P=.28). CONCLUSION Bypass graft markers reduce contrast and radiation use in follow-up coronary angiography and reduce incidence of contrast-induced acute kidney injury.

Research paper thumbnail of Construction Of Soundlevel Meterwithits Unique Applications

International Journal of Scientific & Technology Research, 2014

The objective of the paper is to show people the vast application of sound level meter which coul... more The objective of the paper is to show people the vast application of sound level meter which could change human life for good. For this purpose we construct a sound level meter for domestic purpose which could be used to change the behavior of peoples ———————————————————— Introductionobjective of the paper is to show how to construct a sound level meter and interface it with computer by using the microcontroller. This could be used in wide range of application. The main feature of sound level meter is the flexibility due to user define threshold value and this will also show graphical representation of sound level and the main challenges in its construction was that it follow A frequency response, easy to install and be inexpensive. Construction of Meter Block diagram of sound level meter

Research paper thumbnail of 11 – Peripheral Vascular Intervention

Research paper thumbnail of The Effect of Routine Coronary CT Angiogram Prior to Invasive Coronary Angiography Compared to Invasive Coronary Angiography Alone on Contrast Dose, Procedure Time, Radiation Dose, and Contrast Induced Nephropathy Among Patients with Prior Cabg: A Meta-Analysis of Prospective Studies

Journal of the American College of Cardiology, Mar 1, 2023

Research paper thumbnail of Atrial Fibrillation as Predictor of Outcomes in Patients with Spontaneous Coronary Artery Dissection

Journal of the American College of Cardiology

Research paper thumbnail of Use of Cerebral Embolic Protection Device is Associated with Improved Survival Amongst Patients Undergoing Transcatheter Aortic Valve Replacement: Updated Meta-Analysis

Journal of the American College of Cardiology

Research paper thumbnail of Regional and Temporal Variations in the Incidence of Spontaneous Coronary Artery Dissection (Scad): Insights from the National Inpatient Sample (Nis)

Journal of the American College of Cardiology

Research paper thumbnail of Pulmonary Hypertension as a Predictor for Increased Mortality in Patients Undergoing Percutaneous Left Atrial Appendage Occluder Device Placement

Journal of the American College of Cardiology

Research paper thumbnail of Troubleshooting an Impella- Novel Snaring Technique for De-Kinking the Impella CP

Journal of the American College of Cardiology

Research paper thumbnail of Abstract 13615: Mortality Trends And Regional Variations Of Aortic Aneurysm And Dissection In The United States

Circulation

Introduction: Aortic dissection and aortic aneurysm represent significant health risk as they are... more Introduction: Aortic dissection and aortic aneurysm represent significant health risk as they are associated with very high mortality. Incidence of aortic dissection is low and estimated to be 5-30/100,000 hospitalized patients. Similarly, aortic aneurysms have low incidence (depending upon location) and high mortality (over 80%). Combined mortality associated with aortic aneurysm or dissection and its contemporary trends in the U.S. are not well known. Methods: In this retrospective study death certificate data were retrieved from the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (WONDER) database for 1999-2018. Mortality for aortic aneurysm and dissection ICD-10 code-I71 as an underlying cause of death were queried from 1999-2018. This duration was further stratified into five-year periods. WONDER database is publicly available de-identified data collected by CDC that reports the underlying cause of death across the United States....

Research paper thumbnail of Abstract 13606: Is Pulmonary Hypertension a Poor Prognostic Sign in Patients Hospitalized for Transcatheter Aortic Valve Replacement

Circulation

Introduction: Pulmonary hypertension (PH) is common in patients with severe aortic stenosis (AS).... more Introduction: Pulmonary hypertension (PH) is common in patients with severe aortic stenosis (AS). The prevalence of PH in transcatheter aortic valve replacement (TAVR) patients is reported upto 78% and causes significant morbidity and mortality. We queried the National Inpatient Sample (NIS) database to explore the different outcomes of patients hospitalized for TAVR with and without the history of PH. Hypothesis: PH may increase mortality in hospitalized patients undergoing TAVR. Methods: This is a retrospective cohort study utilizing the 2016-2017 National Inpatient Sample. We identified patients hospitalized for TAVR with and without the history of PH using ICD10 codes. The primary outcome was inpatient mortality. The secondary outcomes were cost of hospitalization, and length of stay (LOS). Multivariate regression was used to adjust for potential confounders including age, gender, race, pulmonary embolism, acute coronary syndrome, heart block, left bundle branch block (LBBB), di...

Research paper thumbnail of Regional Variations in Premature Cardiovascular Mortality, 1999-2018

Journal of the American College of Cardiology

Research paper thumbnail of Premature Mortality in Males Due to Heart Failure in the United States from 2010-2018

Journal of the American College of Cardiology, Mar 1, 2022

Research paper thumbnail of Comparison of Outcomes for Non-ST Elevation Acute Myocardial Infarction in Weekday vs Weekend Admissions: The Weekend Effect

Journal of Community Hospital Internal Medicine Perspectives

Background: Recent literature shows that reduced staffing over the weekends in hospitals may comp... more Background: Recent literature shows that reduced staffing over the weekends in hospitals may compromise patient care with acute conditions like acute coronary syndrome (ACS). Objective: Our study evaluated differences in the outcomes between patients presenting with non-ST segment elevation acute coronary syndrome (NSTE-ACS) on weekends versus those coming on weekdays. Methods: A single-center retrospective study was performed on NSTE-ACS patients. Data were analyzed using SPSS version 22 to calculate an independent sample t-test value for significance between the two groups. Results: The mean DTB time for patients admitted over the weekend was significantly higher than those admitted over weekdays (p ¼ 0.000). The mean peak troponin level and length of stay (LOS) for patients admitted over the weekends vs. weekdays was significantly higher by 5 ng/dL (9.71 ± 5.23 vs. 4.194 ± 2.60, p ¼ 0.0001) and 24 h (72 ± 10 vs. 48 ± 6 h, p ¼ 0.003), respectively. While the mean left ventricular ejection fraction (EF) of patients on discharge was lower by 5% for patients admitted over the weekend compared to patients admitted on weekdays (p ¼ 0.001). Conclusion: NSTE-ACS patients admitted over the weekends have a significantly higher myocardial injury evidenced by an increased LOS, higher peak troponin levels, and reduced EF due to delayed PCI compared to weekday admissions.

Research paper thumbnail of Racial Disparities in Outcomes of Arrhythmias Among Patients Undergoing Transcatheter Aortic Valve Replacement: A National Population Based Study

Journal of the American College of Cardiology, 2021

Research paper thumbnail of One Case, Many Options

Research paper thumbnail of A Survey Paper on Security Issues in Satellite Communication Network infrastructure

Satellite communication is one of the most popular next generation communication technologies for... more Satellite communication is one of the most popular next generation communication technologies for global communication networks in parallel to terrestrial communication networks. In modern age military intelligence, navigation & positioning, weather forecasting, digital video Broadcasting (DVB), and broadband internet services, are the few demanding applications of Satellite communication. Although Satellite communication is cost effective solution for such long distance communication application, However security over the link is still a major concern in satellite communication. Due to limitations such as high bit error rate, power control, large distance between end nodes, high link delays because of large round trip times, and link availability, common security techniques incorporate a lot of issues in implementation of proper secure communication over the satellite links. In this survey paper, we explore the importance of security, trivial and currently deployed security tools, ...

Research paper thumbnail of Symptomatic high-risk congenital coronary anomaly

Heart and Mind, 2017

Anomalous coronary arteries are rare entities with certain categories being potentially malignant... more Anomalous coronary arteries are rare entities with certain categories being potentially malignant with the risk of sudden cardiac death. We present two cases of the highest risk variant consisting of an anomalous left coronary artery arising from the right sinus of Valsalva traversing between the aorta and pulmonary artery leading to recurrent syncope and chest pain in middle-aged patients.

Research paper thumbnail of Realization of Proportional-Integral Stirring Controller for Mixing Operation in Microbioreactor

In this paper, we presented the establishment of a cheap and simple stirring platform for microbi... more In this paper, we presented the establishment of a cheap and simple stirring platform for microbioreactor operation. The stirring platform was designed to provide necessary mixing via magnetic stirrer bar for a microbioreactor setup. The microbioreactor (volume ~ 300 L) used in this investigation was fabricated out of the poly(methylmethacrylate) (PMMA) polymer material via micromachining. Programs for the control routines were written in LabVIEW TM software (National Instruments, Austin, TX, USA), and were implemented by interfacing the LabVIEW TM programs with a data acquisition (DAQ) card (NI USB-6343, National Instruments, Austin, TX, USA) for data logging and sending signals to actuators. The paper first described the details of the mechanical design of the stirring platform and the microbioreactor prototype used in the work. Secondly, experimental results obtained to assess the mixing quality of the reactor and to characterize the performance of the controller in terms of con...

Research paper thumbnail of 859: Intensive Care Units with High Versus Low Annual Volume of Acute Myocardial Infarction

Critical Care Medicine, 2012

Research paper thumbnail of Utility of Radiopaque Bypass Graft Markers During Coronary Angiography Following Coronary Artery Bypass Graft Surgery

The Journal of invasive cardiology, 2020

BACKGROUND Radiopaque bypass graft markers allow easy visualization of the location of the graft ... more BACKGROUND Radiopaque bypass graft markers allow easy visualization of the location of the graft and can minimize contrast use and radiation exposure during follow-up coronary angiography. METHODS This retrospective study analyzed coronary artery bypass graft patients who underwent subsequent coronary angiography in the John Cochrane Veterans Affairs Medical Center from January 2009 until September 2017. RESULTS Patients who underwent diagnostic coronary angiography with proximal graft markers required less contrast use (P<.02) and less fluoroscopy time (P<.01). The presence or absence of proximal graft markers had no significant difference on the rise of creatinine following coronary angiography (P=.28). CONCLUSION Bypass graft markers reduce contrast and radiation use in follow-up coronary angiography and reduce incidence of contrast-induced acute kidney injury.

Research paper thumbnail of Construction Of Soundlevel Meterwithits Unique Applications

International Journal of Scientific & Technology Research, 2014

The objective of the paper is to show people the vast application of sound level meter which coul... more The objective of the paper is to show people the vast application of sound level meter which could change human life for good. For this purpose we construct a sound level meter for domestic purpose which could be used to change the behavior of peoples ———————————————————— Introductionobjective of the paper is to show how to construct a sound level meter and interface it with computer by using the microcontroller. This could be used in wide range of application. The main feature of sound level meter is the flexibility due to user define threshold value and this will also show graphical representation of sound level and the main challenges in its construction was that it follow A frequency response, easy to install and be inexpensive. Construction of Meter Block diagram of sound level meter

Research paper thumbnail of 11 – Peripheral Vascular Intervention