Background:The strategy for early discharge after primary percutaneous coronary intervention (PCI) could have substantial financial benefits, especially in low-middle income countries. However, there is a lack of local evidence on feasibility and safety of the strategy for early discharge. Therefore, the aim of this study was to assess the safety of early discharge after primary PCI in selected low-risk patients in the population of Karachi, Pakistan. Methods: In this study 600 consecutive low-risk patients who were discharged within 48 hours of primary PCI were put under observation for major adverse cardiac events (MACE) after 7 and 30 days of discharge respectively. Patients were further stratified into discharge groups of very early (≤ 24 hours) and early (24 to 48 hours). Results: The sample consisted of 81.8% (491) male patients with mean age of 54.89 ± 11.08 years. Killip class was I in 90% (540) of the patients. The majority of patients (84%) were discharged within 24 hours of the procedure. Loss to follow-up after rate at 7 and 30 days was 4% (24) and 4.3% (26) respectively. Cumulative MACE rate after 7 and 30 days was observed in 3.5% and 4.9%, all-cause mortality in 1.4% and 2.3%, cerebrovascular events in 0.9% and 1.4%, unplanned revascularization in 0.9% and 1.2%, re-infarction in 0.3% and 0.5%, unplanned re-hospitalization in 0.5% and 0.5%, and bleeding events in 0.5% and 0.5% of the patients respectively. Conclusion:It was observed that very early (≤ 24 hours) discharge after primary PCI for lowrisk patients is a safe strategy subjected to careful pre-discharge risk assessment with minimal rate of MACE after 7-days as well as 30-days.

The estimated depth of formation of authigenic dolomite concretions in the Middle Ordovician Cloridorme Formation, Quebec, ranges from < 1 m to 150–200 m below sea floor (mbsf) (mostly between < 1 and 25 mbsf), based on centre‐to‐margin variations in minus‐cement porosity (80–90% to 45–75%). Formation depths are > 350 mbsf (25–17% porosity) in the Lower Ordovician Levis Formation. Outward‐decreasing δ13CVPDB values (10·2–0·8‰) suggest precipitation in the methane generation zone with an increasing contribution of light carbonate derived by advection from thermocatalytic reactions at depth. Anomalously low δ18OVPDB values (centre‐to‐margin variations of −0·4 to −7·5‰) give reasonable temperatures for the concretion centres only if the δ18O of Ordovician sea water was negative (−6‰) and the bottom water was warm (> 15 °C). The 3–5‰ lower values for the concretion margins compared with the centres can be explained if, in addition, volcanic‐ash alteration, organic‐matter decomposition and/or advection of 18O‐depleted water lowered the δ18O of the pore water further by 2·0–4·0‰ during the first 25–200 m of burial. Reasonable growth temperatures for the margins of 17–20 °C are compatible with a lowering of the isotopic ratios by 1 to < 1·3‰ as a temperature effect. The systematic concentric isotope zonation of the concretions suggests that the well‐ordered near‐stoichiometric dolomite is a primary feature and not the result of recrystallization. Diagenetic dolomite beds of the Cloridorme Formation appear to have formed by coalescence of concretions, as shown by randomly sampled traverses that indicate formation at different subsurface depths. Growth of the Cloridorme dolomites was probably limited by calcium availability, at least 50% of which was derived from connate water, and the remainder by diffusion from sea water. Dolomite precipitation was favoured over calcite by very high sedimentation rates, the abundance of marine organic matter in the host sediment and a correspondingly thin sulphate reduction zone. Deep‐seated concretion growth in the Levis Formation required either internal sources for the participating ions (carbonate dissolution event) or porewater advection along faults.

Background Acute myocardial infarction (AMI) is the most life-threatening manifestation of coronary artery diseases. The majority of deaths in AMI are due to arrhythmias. Therefore, the aim of this study was to evaluate the incidence and risk factors and outcomes of cardiac arrhythmias in AMI patients undergoing primary percutaneous coronary intervention (PCI) during the first 24 hours of the index hospitalization. Methodology This prospective observational study was conducted at the adult cardiology department of the National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan. Patients undergoing primary PCI were included in this study. All the patients were kept under observation for the first 24 hours of AMI and monitored through telemetry system monitoring and the incidence of cardiac arrhythmias and the outcomes were recorded. Results A total of 110 patients were included; the mean age was 59.6±13.1 years. Most of them were male (70.9%). Arrhythmias were observed in 89.1% of the patients, with 169 episodes. The accelerated idioventricular rhythm was the most common type of arrhythmia (37.3%) followed by sinus tachycardia (36.4%), ventricular tachycardia (22.7%), and complete heart block (20.0%). Lethal arrhythmias were observed in 64.5% (71) of the patients. During the hospital course, 65.5% developed arrhythmias during arrival to balloon time, 30% during the procedure, and 53.6% within 24 hours of the procedure. The in-hospital mortality rate was 15.5% with a significant association with the development of lethal arrhythmias within 24 hours of the procedure (21.1% vs. 5.1%; p=0.026). Conclusions The incidence of arrhythmias within 24 hours of hospitalization is high in patients with ST-elevation myocardial infarction (STEMI) undergoing primary PCI, and it has been observed to be associated with an increased rate of in-hospital mortality.

Background: Stent thrombosis (ST) remains the most feared complication of percutaneous coronary intervention (PCI). Therefore, this study aimed to determine acute and sub-acute ST incidence, predictors, and outcomes after primary PCI. Methods: This prospective observational study included patients who had undergone primary PCI at a tertiary care cardiac center. All the patients were followed at 30-days of index hospitalization for the incidence of acute or sub-acute ST. ST was further categorized as definite, probable, or possible per the Academic Research Consortium definition. All the survivors of ST were followed after 6-months for the incidence of major adverse cardiovascular events. Results: An aggregate of 1756 patients were included with 79% (1388) male patients and mean age was 55.59 ± 11.23 years. The incidence of ST was 4.9% (86) with 1.3% (22) acute and 3.6% (64) sub-acute. ST was categorized as definite in 3.3% (58) and probable in 1.6% (28). Independent predictor of ST were observed to be male gender (odds ratio (OR); 2.51 [1.21–5.2]), left ventricular end-diastolic pressure ≥20 mmHg (OR; 2.55 [1.31–4.98]), and pre-procedure thrombolysis in myocardial infarction (TIMI) flow 0 (OR; 3.27 [1.61–6.65]). Cumulative all-cause mortality among patients with ST after 164.1 ± 76.2 days was 46.5% (40/86). Conclusion: We observed a substantial number of patients vulnerable to the acute or sub-acute ST after primary PCI. Male gender, LVEDP, pre-procedure TIMI flow grade can be used to identify and efficiently manage highly vulnerable patients.

Background Significance of total ischemic time (TIT) in the context of ST-segment elevation myocardial infarction (STEMI) is still controversial. Therefore, in this study, we have evaluate the association of TIT with immediate outcomes in STEMI patients in whom recommended door to balloon (DTB) time of less than 90 min was achieved. Results A total of 5730 patients were included in this study, out of which 80.9% were male and median age was 55 [61–48] years. The median DTB was observed to be 60 [75–45] min and onset of chest pain to emergency room (ER) arrival time was 180 [300–120] min. Prolonged TIT was associated with poor pre-procedure thrombolysis in myocardial infarction (TIMI) flow grade (p = 0.022), number of diseased vessels (p = 0.002), use of intra-aortic balloon pump (p = 0.003), and in-hospital mortality (p = 0.002). Mortality rate was 4.5%, 5.7%, and 7.8% for the patients with TIT of ≤ 120 min, 121 to 240 min, and > 240 min, respectively. Thirty days’ risk of mortality on TIMI score was 4.97 ± 7.09%, 5.01 ± 6.99%, and 7.12 ± 8.64% for the patients with TIT of ≤ 120 min, 121 to 240 min, and > 240 min, respectively. Conclusions Prolonged total ischemic was associated with higher in-hospital mortality. Therefore, TIT can also be considered in the matrix of focus, along with DTB time and other clinical determinants to improve the survival from STEMI.